CJEU, 1st chamber, April 7, 2016, No C-324/14

THE COURT (First Chamber),

1 This request for a preliminary ruling concerns the interpretation of Articles 2, 44 and 48(3) of Directive 2004/18/EC of the European Parliament and of the Council of 31 March 2004 on the coordination of procedures for the award of public works contracts, public supply contracts and public service contracts (OJ 2004 L 134, p. 114).

2 The request has been made in proceedings between Partner Apelski Dariusz ('Partner') and Zarzad Oczyszczania Miasta (Warsaw municipal cleansing authority) concerning its exclusion from the procedure for the award of a public contract for the comprehensive mechanical cleansing of roadways of the city of Warsaw (Poland) in the years from 2014 to 2017.

Legal context

EU law

Directive 2004/18

3 Recital 46 of the contested directive reads as follows:

'Contracts should be awarded on the basis of objective criteria which ensure compliance with the principles of transparency, non-discrimination and equal treatment and which guarantee that tenders are assessed in conditions of effective competition. As a result, it is appropriate to allow the application of two award criteria only: "the lowest price" and "the most economically advantageous tender".

To ensure compliance with the principle of equal treatment in the award of contracts, it is appropriate to lay down an obligation - established by case-law - to ensure the necessary transparency to enable all tenderers to be reasonably informed of the criteria and arrangements which will be applied to identify the most economically advantageous tender. ...'

4 Article 2 of that directive, entitled 'Principles of awarding contracts', provides:

'Contracting authorities shall treat economic operators equally and non-discriminatorily and shall act in a transparent way.'

5 Article 44 of that directive, entitled 'Verification of the suitability and choice of participants and award of contracts', provides:

'1. Contracts shall be awarded on the basis of the criteria laid down in Articles 53 and 55, taking into account Article 24, after the suitability of the economic operators not excluded under Articles 45 and 46 has been checked by contracting authorities in accordance with the criteria of economic and financial standing, of professional and technical knowledge or ability referred to in Articles 47 to 52, and, where appropriate, with the non-discriminatory rules and criteria referred to in paragraph 3.

2. The contracting authorities may require candidates and tenderers to meet minimum capacity levels in accordance with Articles 47 and 48.

The extent of the information referred to in Articles 47 and 48 and the minimum levels of ability required for a specific contract must be related and proportionate to the subject matter of the contract.

These minimum levels shall be indicated in the contract notice.

...'

6 Article 47(2) of Directive 2004/18 entitled 'Economic and financial standing', provides:

'An economic operator may, where appropriate and for a particular contract, rely on the capacities of other entities, regardless of the legal nature of the links which it has with them. It must in that case prove to the contracting authority that it will have at its disposal the resources necessary, for example, by producing an undertaking by those entities to that effect.'

7 Article 48 of Directive 2004/18 entitled '[t]echnical and/or professional ability' states:

'1. The technical and/or professional abilities of the economic operators shall be assessed and examined in accordance with paragraphs 2 and 3.

2. Evidence of the economic operators' technical abilities may be furnished by one or more of the following means according to the nature, quantity or importance, and use of the works, supplies or services:

(a) ...

(ii) a list of the principal deliveries effected or the main services provided in the past three years, with the sums, dates and recipients, whether public or private, involved. ...

...

...

3. An economic operator may, where appropriate and for a particular contract, rely on the capacities of other entities, regardless of the legal nature of the links which it has with them. It must in that case prove to the contracting authority that it will have at its disposal the resources necessary for the execution of the contract, for example, by producing an undertaking by those entities to place the necessary resources at the disposal of the economic operator.

...'

8 Article 51 of Directive 2004/18, headed 'Additional documentation and information', is worded as follows:

'The contracting authority may invite economic operators to supplement or clarify the certificates and documents submitted pursuant to Articles 45 to 50.'

9 Article 54 of Directive 2004/18 entitled 'Use of electronic auctions' states:

'1. Member States may provide that contracting authorities may use electronic auctions.

...

4. Before proceeding with an electronic auction, contracting authorities shall make a full initial evaluation of the tenders in accordance with the award criterion/criteria set and with the weighting fixed for them.

All tenderers who have submitted admissible tenders shall be invited simultaneously by electronic means to submit new prices and/or new values; ...

...

8. After closing an electronic auction contracting authorities shall award the contract in accordance with Article 53 on the basis of the results of the electronic auction.

Contracting authorities may not have improper recourse to electronic auctions nor may they use them in such a way as to prevent, restrict or distort competition or to change the subject matter of the contract, as put up for tender in the published contract notice and defined in the specification.'

Directive 2014/24/EU

10 Recital 2 of Directive 2014/24/EU of the European Parliament and of the Council of 26 February 2014 on public procurement and repealing Directive 2004/18/EC (OJ 2014 L 94, p. 65) reads as follows:

'... the public procurement rules adopted pursuant to Directive 2004/17/EC ... should be revised and modernised in order to increase the efficiency of public spending, facilitating in particular the participation of small and medium-sized enterprises (SMEs) in public procurement ... There is also a need to clarify basic notions and concepts to ensure legal certainty and to incorporate certain aspects of related well-established case-law of the Court of Justice of the European Union.'

11 Article 63 of Directive 2014/24, entitled 'Reliance on the capacities of other entities', states as follows:

'1. With regard to criteria relating to economic and financial standing as set out pursuant to Article 58(3), and to criteria relating to technical and professional ability as set out pursuant to Article 58(4), an economic operator may, where appropriate and for a particular contract, rely on the capacities of other entities, regardless of the legal nature of the links which it has with them. With regard to criteria relating to the educational and professional qualifications as set out in point (f) of Annex XII Part II, or to the relevant professional experience, economic operators may however only rely on the capacities of other entities where the latter will perform the works or services for which these capacities are required. Where an economic operator wants to rely on the capacities of other entities, it shall prove to the contracting authority that it will have at its disposal the resources necessary, for example, by producing a commitment by those entities to that effect.

...

2. In the case of works contracts, service contracts and siting or installation operations in the context of a supply contract, contracting authorities may require that certain critical tasks be performed directly by the tenderer itself ...'

12 Under Article 90(1) of that directive:

'Member States shall bring into force the laws, regulations and administrative provisions necessary to comply with this Directive by 18 April 2016. ...'

Polish law

13 Directive 2004/18 was transposed into the Polish national legal system by the Law on public contracts (codified text DZ. U of 2013, headings 907, 984, 1047 and 1473, and Dz. U of 2014, heading 423, 'Law on public contracts').

14 Article 26(2b) of the Law on public contracts provides:

'The economic operator may rely on the knowledge and experience, technical capacity, staff able to perform the contract or financial capacities of other entities, regardless of the legal nature of the links which it has with them. In that case the economic operator is required to prove to the contracting authority that it will have at its disposal the resources necessary to perform the contract, inter alia by producing for that purpose a written undertaking by those entities that they will make available to it the necessary resources for the period during which they are used to perform the contract. ...'

15 Article 83(2) and (3) of the Law on public contracts states:

'2. The contracting authority may permit the submission of tenders for lots, where the subject matter of the contract can be divided.

3. In the case referred to in paragraph 2 the economic operator may submit tenders for one or more lots, unless the contracting authority has specified a maximum number of lots for which one economic operator may submit tenders.'

16 Article 91b(1) of the Law on public contracts provides:

'The contracting authority shall invite electronically all the economic operators which have submitted non-rejected tenders to take part in an electronic auction.'

17 According to Article 93(1)(7) of the Law on public contracts:

'The contracting authority shall annul the procedure for the award of the contract where ... the award procedure is vitiated by an irreparable defect which prevents the conclusion of a non-annullable public contract.'

18 Article 1(6) of the Regulation of the president of the Council of Ministers of 19 February 2013 on the type of documents which may be required by the a contracting authority from an economic operator and the method of production of those documents (Dz. U. of 2013, heading 231) is worded as follows:

'If, in order to establish that it meets the conditions referred to in Article 22(1) of the [Law on public contracts], an economic operator relies on the capacities of other entities pursuant to the provisions of Article 26(2b) of the [Law on public contracts], the contracting authority, in order to determine whether the economic operator will have capacities of other bodies to the extent necessary for the proper performance of the contract or whether the link between the economic operator and those entities does in fact ensure access to those capacities may require:

(1) with regard to the conditions referred to in Article 22(1)(4) of the [Law on public contracts], the documents listed in Article 22(1)(9) to (11), and the same for other documents relating to the economic and financial standing, as laid down in the tender notice or the tender specifications;

(2) documents relating in particular to:

(a) the extent of the resources of another entity which the economic operator is able to access;

(b) the rules governing the use by the economic operator of the resources of another entity in order to perform the contract;

(c) the nature of the link between an operator and another entity; and

(d) the extent and duration of the participation of another entity in the performance of the contract.'

The dispute in the main proceedings and the questions referred for a preliminary ruling

19 It is apparent from the order for reference that, in December 2013, the Warsaw municipal cleansing authority initiated a procedure for the award of a public contract for the comprehensive mechanical cleansing of roadways in Warsaw in the winter and summer seasons of 2014 to 2017. The winter cleansing, which is the subject of that contract consists essentially in preventing and removing ice by salting and using snow-ploughs on certain categories of municipal roadways. Summer cleansing involves sweeping and wet cleaning of roadways.

20 The Warsaw municipal cleansing authority chose to conduct a tendering procedure which was to close with an electronic auction. The subject matter of the contract was divided into eight lots, corresponding to different districts of Warsaw, thereby allowing each tenderer either to submit a tender for the whole of that contract or a partial tender.

21 As provided for in the tender specifications, in order to demonstrate its technical abilities, each tenderer was required to submit a list of winter maintenance services for roadways with pre-wetting technology provided in the three years prior to the expiry of the deadline for submitting the tender. The total value of those services had to be at least PLN 1 000 000 (approximately EUR 224 442) for each of the eight lots of the contract at issue. Therefore, in order to submit a tender for the whole contract, a tenderer had to prove that it had provided services with a value of at least PLN 8 000 000 (approximately EUR 1 795 537).

22 Following the publication in the Official Journal of the European Union of the tender notice, Partner put itself forward as a candidate for the whole contract, stating that in the previous 3 years it had supplied 14 services, including 12 based on its own experience and 2 based on the experience of PUM z o.o. ('PUM'), which is established in Grudziadz (Poland), a town situated approximately 230 km from Warsaw.

23 In addition, it attached to its tender an undertaking by PUM, by which the latter made its capacities available to Partner, in particular, its consulting services including, among others, training for Partner's employees and help to resolve any problems which might arise at the performance stage of the contract. Partner also stated that, for the purposes of the performance of the contract that cooperation was to be governed by a contract between the two undertakings.

24 On 26 February 2014, the Warsaw municipal cleansing authority invited Partner to provide further details of the activities that PUM carried out and the effect that those activities might have on the quality and efficiency of the services provided in Warsaw, taking account, in particular, of the distance between Grudziadz and Warsaw.

25 Since it was not satisfied by Partner's answer, and it took the view that PUM's knowledge and experience could not be made available without the personal, actual participation of that company in the performance of the contract at issue, by letter of 11 March 2014, the Warsaw municipal cleansing authority requested Partner to supplement the documents in that respect.

26 In its answer of 18 March 2014, Partner challenged the approach adopted by the Warsaw municipal cleansing authority, and requested that its tender be taken into consideration when awarding each of the eight lots of that contract in a certain order of priority.

27 The Warsaw municipal cleansing authority nonetheless rejected Partner's tender in its entirety and closed the procurement procedure at issue after holding an electronic auction.

28 Therefore, Partner brought an action before the Krajowa Izba Odwolawcza (National Appeal Chamber) in order to obtain the annulment of the decision by which it has been excluded from the procurement procedure at issue and that which adopted the most advantageous offers for the various lots of that contract. Furthermore, it requested that the tenders submitted in that procurement procedure be re-examined and that it be allowed to take part in a new electronic auction.

29 In those circumstances, Krajowa Izba Odwolawcza (National Appeal Chamber), decided to stay proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:

'(1) Can Article 48(3) of Directive 2004/18 in conjunction with Article 2 thereof, be interpreted, where it states that "where appropriate" an economic operator may rely on the capacities of other entities, as covering any situation where a particular economic operator does not have the skills required by the contracting authority and wishes to rely on the capacities of other entities? Or must the indication that an economic operator may rely on the resources of other entities only "where appropriate" be regarded as a restriction indicating that such reliance may be had only exceptionally and not as a rule when providing evidence of the skills of economic operators in procedures for the award of public contracts?

(2) Can Article 48(3) of Directive 2004/18, in conjunction with Article 2 thereof, be interpreted as meaning that reliance by an economic operator on the capacities of other entities in terms of their knowledge and experience "regardless of the legal nature of the links which it has with them" and "having at its disposal the resources" of those entities denote that during performance of the contract an economic operator need not have links with those entities or can have very loose and vague links, that is to say, it can perform the contract independently (without the involvement of another entity) or such participation can consist of "advice", "consultation", "training" and the like? Or must Article 48(3) be interpreted as meaning that the entity on whose capacities the economic operator relies must actually and personally perform the contract in so far as its capacities were declared?

(3) Can Article 48(3) of Directive 2004/18, in conjunction with Article 2 thereof, be interpreted as meaning that an economic operator which has its own experience but to a lesser degree than it would like to indicate to the contracting authority (for example, insufficient experience to submit a tender for the whole contract) may rely additionally on the capacities of other entities to improve its situation in the procedure?

(4) Can Article 48(3) of Directive 2004/18, in conjunction with Article 2 thereof, be interpreted as meaning that in the contract notice or the tendering specifications the contracting authority can (or even must) lay down the rules under which the economic operator may rely on the capacities of other entities, for example in what way the economic operators must participate in the performance of the contract, in what way the capacity of the economic operator and another entity can be combined, and whether the other entity will bear joint and several liability with the economic operator for the due performance of the contract in so far as the economic operator has relied on its capacities?

(5) Does the principle of equal and non-discriminatory treatment of economic operators set out in Article 2 of Directive 2004/18 allow reliance on the capacities of another entity under Article 48(3) where the capacities of two or more entities which do not have the capacities in terms of knowledge and experience required by the contracting authority are combined?

(6) Therefore, does the principle of equal and non-discriminatory treatment of economic operators set out in Article 2 of Directive 2004/18 allow an interpretation of Articles 44 and 48(3) of Directive 2004/18 to the effect that the conditions for participation in the procedure that are laid down by the contracting authority may be fulfilled just formally for the purposes of participating in the procedure and regardless of the actual skills of the economic operator?

(7) Where it is permitted to submit a tender for lots, does the principle of equal and non-discriminatory treatment of economic operators set out in Article 2 of Directive 2004/18 allow an economic operator, after the submission of tenders, to state - for example in the context of the supplementing or explaining of documents - to which lot the resources specified by it in order to prove that the conditions for participation in the procedure have been fulfilled are to be assigned?

(8) Do the principle of equal and non-discriminatory treatment of economic operators and the principle of transparency set out in Article 2 of Directive 2004/18 allow an auction which has been carried out to be annulled and an electronic auction to be repeated where it was carried out improperly in an essential respect, for example where not all economic operators which submitted admissible tenders were invited to participate?

(9) Do the principle of equal and non-discriminatory treatment of economic operators and the principle of transparency set out in Article 2 of Directive 2004/18 allow a contract to be awarded to an economic operator whose tender was selected as a result of such an auction without it being repeated, where it is not possible to determine whether or not the participation of the economic operator which was not taken into consideration would have altered the result of the auction?

(10) In interpreting the provisions of Directive 2004/18, is it permitted to use as a guide to interpretation the content of the provisions of Directive 2014/24 and of the preamble thereto, even though the period for implementing it has not expired, in so far as it explains certain assumptions and intentions of the EU legislature and is not contrary to Directive 2004/18?'

Consideration of the questions referred for a preliminary ruling

Questions 1 to 3, 5 and 6

30 By questions 1 to 3, 5 and 6, which it is appropriate to examine together, the referring court asks the Court of Justice essentially to determine the conditions which must be met in order for an economic operator to rely on the capacities of other entities, within the meaning of Article 48(3) of Directive 2004/18, and to clarify the detailed rules according to which the necessary resources of those entities are to be made available and, therefore, their possible participation in the performance of the contract concerned.

31 In order to answer those questions it must be recalled, as a preliminary point, that, according to Article 44(1) of Directive 2004/18, it is for the contracting authorities to check the suitability of the candidates or tenderers in accordance with the criteria referred to in Articles 47 to 52 thereof.

32 Furthermore, under Article 44(2) of Directive 2004/18 a contracting authority may require candidates or tenderers to meet minimum levels of economic and financial standing and technical and professional ability in accordance with Articles 47 and 48 of that directive.

33 According to the Court's settled case-law, Articles 47(2) and 48(3) of Directive 2004/18 recognise the right of every economic operator to rely, for a particular contract, upon the capacities of other entities, regardless of the nature of the links which it has with them, provided that it proves to the contracting authority that it will have at its disposal the resources necessary for the performance of the contract (see, to that effect, judgment in Swm Costruzioni 2 and Mannocchi Luigino, C-94/12, EU:C:2013:646, paragraphs 29 and 33).

34 Such an interpretation is consistent with the aim of the widest possible opening-up of public contracts to competition pursued by the relevant directives to the benefit not only of economic operators but also of contracting authorities. In addition that interpretation also facilitates the involvement of small- and medium-sized undertakings in the contracts procurement market, an aim also pursued by Directive 2004/18, as stated in recital 32 thereof. (judgment in Swm Costruzioni 2 and Mannocchi Luigino, C-94/12, EU:C:2013:646, paragraph 34 and the case-law cited).

35 It follows that, taking account of its importance in the EU legislation on public procurement, the right established in Articles 47(2) and 48(3) of that directive constitutes a general rule which the contracting authorities must take into account when they exercise their powers of verification of the suitability of the tenderer to perform a specific contract.

36 In those circumstances, the fact that, under Article 48(3) of Directive 2004/18, an economic operator may rely on the resources of other entities 'where appropriate' cannot be interpreted as the referring court, in particular, appears to suggest, as meaning that it is only exceptionally that such an operator may rely on the resources of third party entities.

37 That being said, it must be stated, first, that, although it is free to establish links with the entities on whose resources it relies, and to choose the legal nature of those links, the tenderer is nonetheless required to produce evidence that it actually has available to it the resources of those entities or undertakings, which it does not itself own, and which are necessary for the performance of the contract (see to that effect, judgment in Holst Italia, C-176/98, EU:C:1999:593, paragraph 29 and the case-law cited).

38 Thus, in accordance with Articles 47(2) and 48(3) of Directive 2004/18, a tenderer may not rely on the resources of other entities in order to satisfy in a purely formal manner the conditions required by the contracting authority.

39 Second, as the Court has already held, the provisions of Directive 2004/18 do not preclude the exercise of the right established in Articles 47(2) and 48(3) thereof from being limited in exceptional circumstances (see, to that effect, judgment in Swm Costruzioni 2 and Mannocchi Luigino, C-94/12, EU:C:2013:646, paragraph 36).

40 It is conceivable that there may be works with special requirements necessitating a certain capacity which cannot be obtained by combining the capacities of more than one operator, which, individually, would be inadequate. In such circumstances, the contracting authority would be justified in requiring that the minimum capacity level concerned be achieved by a single economic operator or, where appropriate, by relying on a limited number of economic operators, in accordance with the second subparagraph of Article 44(2) of Directive 2004/18, as long as that requirement is related and proportionate to the subject matter of the contract at issue (judgment in Swm Costruzioni 2 and Mannocchi Luigino, C-94/12, EU:C:2013:646, paragraph 35).

41 Likewise, it is conceivable that, in specific circumstances, having regard to the nature and objectives of a particular contract, the capacities of a third party entity, which are necessary for the performance of a particular contract, cannot be transferred to the tenderer. Accordingly, in such circumstances, the tenderer may rely on those capacities only if the third party entity directly and personally participates in the performance of the contract concerned.

42 In the present case, the referring court expresses doubts as to whether PUM's capacities may genuinely be transferred to Partner so that the resources necessary for the performance of the contract at issue in the main proceedings may be placed at Partner's disposal in accordance with the terms of Article 48(3) of Directive 2004/18, given the fact that the resources in that case are made available simply by providing consultation and training services, without any direct participation by PUM in the performance of that contract.

43 In that connection, it must be observed that the public contract at issue in the main proceedings, described in paragraph 19 of the present judgment, is for the comprehensive mechanical cleansing of the roadways of Warsaw in winter and summer for four consecutive years.

44 In particular, as regards winter cleansing, it is apparent from the order for reference that that service requires specific skills and a detailed knowledge of the topography of the city of Warsaw and, above all, the ability to react immediately in order to attain specific maintenance standards for the roadways within a specific period.

45 Furthermore, that service is based on the use of specific technology requiring a level of experience and a high degree of skill in using it, which alone enables the contract at issue in the main proceedings to be performed properly while avoiding dangerous consequences for road traffic.

46 In those circumstances, the actual performance of such a contract requires the involvement of experienced staff who, inter alia, by directly observing the state of the surface of the roadways and carrying out on-the-spot tests are able to anticipate or, in any event, respond appropriately to the specific needs of that contract.

47 Taking account of the subject matter of the contract at issue in the main proceedings and its objectives, it is conceivable that PUM's proposed involvement, consisting simply in the provision of consultation and training services, cannot be regarded as sufficient in order to guarantee that Partner would have at its disposal the resources necessary for the performance of that contract within the meaning of the case-law set out in paragraph 33 of the present judgment. That is further justified by the fact that, as is apparent from the order for reference, PUM's registered office is situated in the city of Gurdziadz, approximately 230 km from Warsaw.

48 In those circumstances, it is for the referring court, taking account of all the specific facts of the contract at issue in the main proceedings, to determine whether resources would be made available to the tenderer in such a way as to meet the requirements laid down by that case-law.

49 Having regard to the foregoing considerations, the answer to questions 1 to 3, 5 and 6 is that Articles 47(2) and 48(3) of Directive 2004/18, read together with Article 44(2) thereof, must be interpreted as meaning that:

- they recognise the right of all economic operators, as regards a specific contract, to rely on the capacities of other entities, whatever the nature of the links existing between it and those entities, provided that it is proved to the contracting authority that the candidate or tenderer will have at its disposal the resources of those entities necessary for the performance of that contract, and

- it is conceivable that the exercise of that right may be limited, in specific circumstances, having regard to the subject matter of the contract concerned and its objectives. Such is the case, in particular, where the capacities that a third party entity has, which are necessary for the performance of that contract, cannot be transferred to the candidate or the tenderer, so that the latter may rely on those capacities only if that third party entity directly and personally participates in the performance of that contract.

The fourth question

50 By its fourth question, the referring court asks essentially whether Article 48(2) and (3) of Directive 2004/18 must be interpreted as meaning that the contracting authority has the possibility to expressly set out, in the tender notice or the tender specifications, the precise rules under which an economic operator may rely on the capacities of other entities.

51 In order to answer that question, it must be recalled, as stated in paragraphs 33 and 49 of the present judgment, that Articles 47(2) and 48(3) of Directive 2004/18 recognise the right of all economic operators to rely on the capacities of other entities, provided that it is proved to the contracting authority that the candidate or tenderer will have at its disposal the resources necessary for the performance of the contract concerned.

52 For that purpose, although the tenderer must prove that it will actually have at its disposal the resources of the other entity, which it does not itself own and which are necessary for the performance of the contract, it is nonetheless free to choose the legal nature of the links it intends to establish with the other entities on whose capacities it relies in order to perform a particular contract and, on the other, the type of proof of the existence of those links (judgment in Ostas celtnieks, C-234/14, EU:C:2016:6, paragraph 28).

53 Therefore, the contracting authority cannot, in principle, impose express conditions which may impede the exercise of the right of all economic operators to rely on the capacities of other entities, in particular, by indicating in advance the detailed rules according to which the capacities of those other entities may be relied on. That finding applies especially since, in practice, as the European Commission rightly observes, it appears difficult or even impossible for an economic operator to foresee, a priori, all the possible scenarios in which the capacities of other entities may be used.

54 That being said, as acknowledged in answer to questions 1 to 3, 5 and 6, having regard to the subject matter of the contract concerned and its objectives, the exercise of such a right may be limited in specific circumstances such as those set out in paragraphs 39 to 41 of the present judgment.

55 In such circumstances, it cannot be excluded from the outset that the contracting authority may, for the purposes of the proper performance of the contract concerned, expressly set out, in the tender notice or the tender specifications, the specific rules authorising an economic operator to rely on the capacities of other entities.

56 However, if the contracting authority decides to make use of such a possibility, it must ensure that the rules it adopts are related and proportionate to the subject matter and objectives of that contract.

57 Furthermore, such a requirement also helps to ensure compliance with the principle of transparency as regards the rules adopted by the contracting authority, while allowing economic operators the possibility to propose to the contracting authority alternative ways of relying on the capacities of other entities which ensure that those capacities are in fact made available.

58 Accordingly, the answer to question 4 is that Article 48(2) and (3) of Directive 2004/18 must be interpreted as meaning that, having regard to the subject matter of a particular contract and its objectives, the contracting authority may, in specific circumstances, for the purpose of the proper performance of that contract, expressly set out in the tender notice or the tender specifications the specific rules in accordance with which an economic operator may rely on the capacities of other entities, provided that those rules are related and proportionate to the subject matter and objectives of that contract.

The seventh question

59 By question 7, the referring court asks essentially whether the principles of equal treatment and non-discrimination of economic operators, laid down in Article 2 of Directive 2004/18, must be interpreted as meaning that they preclude a contracting authority, after the opening of the tenders submitted in a public procurement procedure, from allowing the request of an economic operator, which has submitted a tender for the whole of the contract concerned, to consider its tender solely for the award of certain lots of that contract.

60 In order to answer that question, it must be recalled that, in accordance with recital 46 and Article 2 of Directive 2004/18, the contracting authorities are required to afford economic operators equal, non-discriminatory and transparent treatment.

61 Thus, first, the principles of equal treatment and non-discrimination require tenderers to be afforded equality of opportunity when formulating their bids, which therefore implies that the bids of all tenderers must be subject to the same conditions. Second, the principle of transparency is essentially intended to preclude any risk of favouritism or arbitrariness on the part of the contracting authority. That obligation implies that all the conditions and detailed rules of the award procedure must be drawn up in a clear, precise and unequivocal manner in the notice or contract documents so that, first, all reasonably informed tenderers exercising ordinary care can understand their exact significance and interpret them in the same way and, secondly, the contracting authority is able to ascertain whether the tenders submitted satisfy the criteria applying to the relevant contract (see, to that effect, judgment in Cartiera dell'Adda, C-42/13, EU:C:2014:2345, paragraph 44 and the case-law cited).

62 Furthermore, as the Court has already held, the principles of equal treatment and non-discrimination and the obligation of transparency preclude any negotiation between the contracting authority and a tenderer during a public procurement procedure, which means that, as a general rule, a tender cannot be amended after it has been submitted, whether at the request of the contracting authority or at the request of the tenderer concerned. It follows that, where the contracting authority regards a tender as imprecise or as failing to meet the technical requirements of the tender specifications, it cannot require the tenderer to provide clarification (judgment in Manova, C-336/12, EU:C:2013:647, paragraph 31 and the case-law cited).

63 However, the Court has explained that Article 2 of Directive 2004/18 does not preclude the correction or amplification of details of a tender, on a limited and specific basis, particularly when it is clear that they require mere clarification, or to correct obvious material errors (judgment in Manova, C-336/12, EU:C:2013:647, paragraph 32 and the case-law cited).

64 To that end, the contracting authority must ensure, in particular, that the request for clarification does not lead to the submission, by a tenderer, of what would appear in reality to be a new tender (see, to that effect, judgment in Manova, C-336/12, EU:C:2013:647, paragraph 36).

65 Furthermore, when exercising its right to ask a tenderer to clarify its tender, the contracting authority must treat tenderers equally and fairly, in such a way that a request for clarification does not appear unduly to have favoured or disadvantaged the tenderer or tenderers to which the request was addressed, once the procedure for selection of tenders has been completed and in the light of its outcome (judgment in Manova, C-336/12, EU:C:2013:647, paragraph 37).

66 In the present case, as is apparent from the order for reference, the Warsaw municipal cleansing authority, having doubts as to whether Partner had the resources necessary for the performance of the contract at issue in the main proceedings, requested that company, after it had submitted its tender, to specify the nature of PUM's participation in the performance of the contract.

67 In answer to that request for clarification, Partner asked the Warsaw municipal cleansing authority, in the event that it considered the experience shown to be insufficient, to allocate the resources Partner relied on to each of the eight lots of the contract at issue in the main proceedings in a certain order of priority, so that a possible rejection would not concern the whole contract, but only the lots in respect of which it did not meet the conditions required.

68 It is common ground that such communication, by which an economic operator indicates to the contracting authority, after the opening of the tenders, the order of priority of the lots of the contract concerned according to which its tender should be assessed, far from being merely a clarification made on a limited or specific basis or a correction of obvious material errors, within the meaning of the case-law set out in paragraph 63 of the present judgment, constitutes, in reality, a substantive amendment which is more akin to the submission of a new tender.

69 It follows that the contracting authority cannot allow an economic operator to clarify its initial offer in such a way without infringing the principles of equal treatment and non-discrimination of economic operators and the obligation of transparency deriving from that, to which the contracting authority is subject under Article 2 of Directive 2004/18 (see, to that effect, judgment in Cartiera dell'Adda, C-42/13, EU:C:2014:2345, paragraph 43).

70 It follows from the foregoing that the answer to question 7 is that the principles of equal treatment and non-discrimination of economic operators, set out in Article 2 of Directive 2004/18, must be interpreted as meaning that, in circumstances such as those at issue in the main proceedings, they preclude a contracting authority, after the opening of the tenders submitted in a public procurement procedure, from acceding to the request of an economic operator which has submitted a tender for the whole of the contract concerned, to take its offer into consideration for the purpose of awarding only certain lots of that contract.

Questions 8 and 9

71 By questions 8 and 9, which it is appropriate to examine together, the referring court asks essentially whether the principle of equal treatment and non-discrimination of economic operators, set out in Article 2 of Directive 2004/18, must be interpreted as meaning that they require the annulment and repetition of an electronic auction in respect of which an economic operator which submitted an admissible tender was not invited to participate, even if it cannot be established that the participation of the excluded operator would have changed the outcome of the auction.

72 In accordance with recital 14 and Article 1(7) of Directive 2004/18, recourse to electronic auctions enables contracting authorities, after an initial full evaluation of the tenders, to ask tenderers to submit new prices, revised downwards, and when the contract is awarded to the most economically advantageous tender, also to improve elements of the tenders other than prices.

73 In such a procedure, as that recital provides, Directive 2004/18 requires that electronic auctions operate in full accordance with the principles of equal treatment, non-discrimination and transparency.

74 For that purpose, first, Article 54(4) of Directive 2004/18 provides for the right of all tenderers which have submitted an admissible tender to be invited to participate in the electronic auction in order to submit new prices and/or new values.

75 Second, Article 54(8), second subparagraph, of that directive explicitly requires the contracting authorities, where they decide to organise an electronic auction, not to have recourse to such a procedure so as to prevent, restrict or distort competition or to change the subject matter of the contract as put up for tender in the published contract notice and defined in the specification.

76 It follows that, when a tenderer submits an admissible tender and thereby satisfies the criteria set out in the tender notice, the contracting authority must, in accordance with Article 54(4) of Directive 2004/18, ensure the tenderer is able to exercise its right to take part where appropriate, in the electronic auction.

77 Therefore, where such a tenderer is not invited to take part in that auction, as the Advocate General observed in paragraph 52 of his Opinion, the principles of equal treatment and non-discrimination, laid down in Article 2 of Directive 2004/18, require the contracting authority to annul and repeat the electronic auction.

78 In that connection, it must be stated that that applies independently of whether its participation would have altered the outcome of the auction or not.

79 The exercise of the tenderer's right to take part in an electronic auction cannot be subject in any way to the result proposed by it and thus, cannot be excluded from the outset by reason of hypothetical considerations expressed by the contracting authority.

80 In other words, as the Krajowa Izba Odwolawcza (National Chamber of Appeal) also pointed out in its order for reference, it is possible that an economic operator which has not been allowed to take part in an electronic auction may have submitted the most advantageous tender, so that the error committed by the contracting authority necessarily requires the annulment and repetition of the auction.

81 Therefore, the answer to questions 8 and 9 is that the principles of equal treatment and non-discrimination of economic operators laid down in Article 2 of Directive 2004/18 must be interpreted as meaning that they require the annulment and repetition of an electronic auction in which an economic operator having submitted an admissible tender has not been invited to take part, even if it cannot be established that the participation of that operator would have altered the outcome of the auction.

Question 10

82 By question 10, the referring court asks essentially whether the provisions of Directive 2004/18 can be interpreted in the light of those of Directive 2014/24, even though the period within which to transpose the latter has not yet expired and provided that its provisions are not contrary to those of Directive 2004/18.

83 In order to answer that question, it must be recalled, as a preliminary point, that, according to settled case-law, the applicable directive is, as a rule, the one in force when the contracting authority chooses the type of procedure to be followed and decides definitively whether it is necessary for a prior call for competition to be issued for the award of a public contract. Conversely, a directive is not applicable if the period prescribed for its transposition expired after that point in time (judgment in Impresa Pizzarotti, C-213/13, EU;C:2014:2067, paragraph 31 and the case-law cited).

84 In the case in the main proceedings, the procurement procedure in question was published on 24 December 2013 while Directive 2014/24 was adopted only on 26 February 2014 and, in any event, the period prescribed for its transposition will expire, in accordance with Article 90 thereof, on 18 April 2016.

85 In those circumstances, Directive 2014/24 is not applicable, ratione temporis, in the main proceedings.

86 Furthermore, to apply Directive 2014/24 which, as appears from its title, repeals Directive 2004/18, before the expiry of its period prescribed for transposition would prevent the Member States, as well as contracting authorities and economic operators from benefitting from a sufficient period in which to adapt to the new provisions introduced by it.

87 That being said, it must be observed, as is clear from the order for reference that, by its question, the referring court asks, inter alia, whether Article 48(3) of Directive 2004/18, which recognises the right of all economic operators to rely on the capacities of other entities for a particular contract, must be interpreted as taking into consideration the content of Article 63(1) of Directive 2014/24, which is the provision corresponding to Article 48.

88 In that connection, it must be observed, as the referring court noted, that Article 48(3) of Directive 2004/18 is formulated in general terms and does not expressly set out the detailed rules according to which an economic operator may rely on the capacities of other entities in a public procurement procedure.

89 However, Article 63(1) of Directive 2014/24 now provides that economic operators may 'only rely on the capacities of other entities where the latter will perform the works or services for which these capacities are required'.

90 Although it is true, as stated, inter alia, by recital 2 of Directive 2014/24, Directive 2014/24 aims to clarify basic notions and concepts to ensure legal certainty and to incorporate certain aspects of related well-established case-law of the Court of Justice of the European Union, the fact remains that Article 63 of that directive introduces substantial amendments as regards the right of an economic operator to rely on the capacities of other entities in the context of public contracts.

91 Far from preserving the continuity of Article 48(3) of Directive 2004/18, and clarifying its scope, Article 63(1) of Directive 2014/24 introduces new conditions which were not provided for under the previous legislation.

92 In those circumstances, that provision of Directive 2014/24 cannot be used as a criterion for the interpretation of Article 48(3) of Directive 2004/18 since there is no question in the present case of dispelling a problem of interpretation concerning the content of the latter provision.

93 Another approach might in some way incorrectly anticipate the application of the new legislation which differs from that laid down by Directive 2004/18, and would be manifestly contrary to the principle of the legal certainty for economic operators, which, as is clear inter alia from recital 2 thereof, is a principle that Directive 2014/24 expressly intends to ensure is observed.

94 In view of the foregoing, the answer to question 10 is that, in circumstances such as those in the main proceedings, the provisions of Article 48(3) of Directive 2004/18 cannot be interpreted in the light of those of Article 63(1) of Directive 2014/24.

Costs

95 Since these proceedings are, for the parties to the main proceedings, a step in the action pending before the national court, the decision on costs is a matter for that court. Costs incurred in submitting observations to the Court, other than the costs of those parties, are not recoverable.

On those grounds, the Court (First Chamber) hereby rules:

1. Articles 47(2) and 48(3) of Directive 2004/18/EC of the European Parliament and of the Council of 31 March 2004 on the coordination of procedures for the award of public works contracts, public supply contracts and public service contracts, read together with Article 44(2) thereof, must be interpreted as meaning that:

- they recognise the right of all economic operators, as regards a specific contract, to rely on the capacities of other entities, whatever the nature of the links existing between it and those entities, provided that it is proved to the contracting authority that the candidate or tenderer will have at its disposal the resources of those entities necessary for the performance of that contract, and

- it is conceivable that the exercise of that right may be limited, in specific circumstances, having regard to the subject matter of the contract concerned and its objectives. Such is the case, in particular, where the capacities that a third party entity has, which are necessary for the performance of that contract, cannot be transferred to the candidate or the tenderer, so that the latter may rely on those capacities only if that third party entity directly and personally participates in the performance of that contract.

2. Article 48(2) and (3) of Directive 2004/18 must be interpreted as meaning that, having regard to the subject matter of a particular contract and its objectives, the contracting authority may, in specific circumstances, for the purpose of the proper performance of that contract, expressly set out in the tender notice or the tender specifications the specific rules in accordance with which an economic operator may rely on the capacities of other entities, provided that those rules are related and proportionate to the subject matter and objectives of that contract.

3. The principles of equal treatment and non-discrimination of economic operators, set out in Article 2 of Directive 2004/18, must be interpreted as meaning that, in circumstances such as those at issue in the main proceedings, they preclude a contracting authority, after the opening of the tenders submitted in a public procurement procedure, from acceding to the request of an economic operator which has submitted a tender for the whole of the contract concerned, to take its offer into consideration for the purpose of awarding only certain lots of that contract.

4. The principles of equal treatment and non-discrimination of economic operators laid down in Article 2 of Directive 2004/18 must be interpreted as meaning that they require the annulment and repetition of an electronic auction in which an economic operator having submitted an admissible tender has not been invited to take part, even if it cannot be established that the participation of that operator would have altered the outcome of the auction.

5. In circumstances such as those in the main proceedings, the provisions of Article 48(3) of Directive 2004/18 cannot be interpreted in the light of those of Article 63(1) of Directive 2014/24/EU of the European Parliament and of the Council of 26 February 2014 on public procurement and repealing Directive 2004/18.