1

In July 2007, the first applicant, the Gmina Miasto Gdynia (‘municipality of Gdynia’) and the Gmina Kosakowo (‘municipality of Kosakowo’) created the second applicant, the company Port Lotniczy Gdynia-Kosakowo sp. z o.o. (‘PLGK’), the ownership of which belongs wholly to those two Polish municipalities, with the aim of converting the military airfield of Gdynia-Oksywie into a civil airport. That airfield is located in the territory of the municipality of Kosakowo in Pomerania, in the north of Poland. That new civil airport, the management of which was entrusted to PLGK, was to become the second most important airport in Pomerania and was to be used predominantly for general air traffic, low cost airlines and charter airlines.

…

5

By decision of 2 July 2013, the Commission opened a formal investigation procedure concerning the measure at issue, under Article 108(2) TFEU, and invited the interested parties to submit their comments (Decision C(2013) 4045 final of 2 July 2013 on measure SA.35388 (2013/C) (ex 2013/NN and ex 2012/N) — Poland — Setting up the Gdynia-Kosakowo airport (OJ 2013 C 243, p. 25) (‘the opening decision’) The Commission received no comments from the interested parties.

…

7

On 11 February 2014, the Commission adopted Decision 2014/883/EU on the measure SA.35388 (13/C) (ex 13/NN and ex 12/N) — Poland — Setting up the Gdynia-Kosakowo Airport (OJ 2014 L 357, p. 51), in which it found that the intended funding project amounted to State aid within the meaning of Article 107(1) TFEU, in particular because, as a result of the public funding by the municipality of Gdynia and the municipality of Kosakowo, PLGK had obtained an economic advantage from which it would not have benefited under normal market conditions. By that decision, the Commission ordered the Polish authorities to recover the State aid paid to PLGK.

…

10

On 26 February 2015, the Commission, in the same measure, withdrew Decision 2014/883 and replaced it by Decision (EU) 2015/1586 on measure SA.35388 (13/C) (ex 13/NN and ex 12/N) — Poland — Setting up the Gdynia-Kosakowo airport (OJ 2015 L 250, p 165) (‘the contested decision’).

11

As regards the withdrawal of Decision 2014/883, the Commission indicated that, in the course of the proceedings before the General Court, it had become apparent that the State aid declared incompatible with the internal market by Decision 2014/883 included certain investments which, according to the opening decision, did not amount to State aid in that they came within the remit of public policy. Those investments covered the construction of buildings for a unit of firefighters, customs officials, airport security guards, as well as police officers and border guards and their equipment (recitals 15 and 16 of the contested decision). On that basis, the Commission decided that Decision 2014/883 should be repealed and replaced by the contested decision. The Commission also took the view that it was not necessary to open a new investigation procedure since the file contained all the elements necessary for the assessment of the measure at issue (recital 18 of the contested decision).

…

16

In the contested decision, the Commission first recalled the context of the formal investigation procedure.

…

18

The investment project was funded by capital injections from the municipalities of Gdynia and Kosakowo, which were intended to cover both investment costs (‘investment aid’) and the operating costs of the airport during the initial phase of its operation (until 2019) (‘operating aid’). The Commission notes that, prior to the notification of the measure by the Polish authorities, the municipalities of Gdynia and Kosakowo had agreed a contribution of a value of approximately PLN 207.48 million (Polish złotys) (approximately EUR 51.87 million) in total for the purposes of implementing the investment project and covering the airport’s losses in the first years of its operation. Over the period 2007-2019, the city of Gdynia was to provide a financial contribution of PLN 142.48 million (approximately EUR 35.62 million). The municipality of Kosakowo paid PLN 100000 (approximately EUR 25000) at the time when the company was set up. The Commission also indicated that the municipality of Kosakowo, over the period 2011-2040, was to make a non-cash contribution of PLN 64.9 million (approximately EUR 16.2 million) by swapping part of the annual rent for the leased land (which the airport operator is obliged to pay to it) for shares in the company operating the airport (recitals 31 and 32 of the contested decision).

19

In the second place, the Commission took the view that the capital injections in favour of PLGK constituted State aid within the meaning of Article 107(1) TFEU. Since the funding had already been made available to PLGK, the Commission also considered that the Polish authorities had failed to comply with the prohibition laid down in Article 108(3) TFEU (recital 191 of the contested decision).

20

In the third place, the Commission analysed whether the aid at issue was compatible with the internal market in the light of, in particular, Article 107(3)(c) TFEU.

…

24

In the fourth place, the Commission stated that the aid at issue had to be refunded to the Polish authorities to the extent to which it had been paid.

25

On that basis, the Commission adopted the contested decision. The operative part of the contested decision reads as follows:

‘Article 1

Decision 2014/883/EU is withdrawn.

Article 2

1.   The capital injections in favour of [PLGK] between 28 August 2007 and 17 June 2013 constitute State aid which has been unlawfully put into effect by [the Republic of] Poland in breach of Article 108(3) [TFEU] and which is incompatible with the internal market, except in so far as these capital injections were spent on investments necessary to carry out the activities that according to the [opening] decision must be considered as falling within the public policy remit.

2.   The capital injections which [the Republic of] Poland is planning to implement in favour of [PLGK] after 17 June 2013 for the conversion of the Gdynia-Kosakowo military airfield into a civil aviation airport constitute State aid which is incompatible with the internal market. The State aid may accordingly not be implemented.

Article 3

1   [The Republic of] Poland shall recover the aid referred to in Article 2(1) from the beneficiary.

2   The sums to be recovered shall bear interest from the date on which they were put at the disposal of the beneficiary until their actual recovery. The interest shall be calculated on a compound basis in accordance with Chapter V of Commission Regulation (EC) No 794/2004 [of 21 April 2004 implementing Council Regulation (EC) No 659/1999 laying down detailed rules for the application of Article 93 of the EC Treaty (OJ 2004 L 140, p. 1)].

3   [The Republic of] Poland shall cancel all outstanding payments of the aid referred to in Article 2(2) with effect from the date of notification of this Decision.

Article 4

1   Recovery of the aid referred to in Article 2(1) and the interest referred to in Article 3(2) shall be immediate and effective.

2   [The Republic of] Poland shall ensure that this Decision is implemented within four months following the date of notification of this Decision.

Article 5

1   Within two months following notification of this Decision, [the Republic of] Poland shall submit the following information to the Commission:

2.   [The Republic of] Poland shall keep the Commission informed of the progress of the national measures taken to implement this Decision until recovery of the aid referred to in Article 2(1) and the interest referred to in Article 3(2) has been completed. It shall immediately submit, on simple request by the Commission, information on the measures already taken and planned to comply with this Decision. It shall also provide detailed information concerning the amounts of aid and recovery interest already recovered from the beneficiary.

Article 6

This Decision is addressed to the Republic of Poland.’

26

By application lodged at the Court Registry on 15 May 2015, the municipality of Gdynia and PLGK brought the present action.

27

By decision of 1 December 2015, the President of the Sixth Chamber of the General Court granted the Republic of Poland leave to intervene in support of the form of order sought by the applicants.

28

By decision of 15 April 2016, the case was assigned to a new Judge-Rapporteur.

29

Following changes in the composition of the Chambers of the General Court, pursuant to Article 27(5) of its Rules of Procedure, the Judge-Rapporteur was assigned to the Seventh Chamber, to which the present case was accordingly attributed.

30

Following a proposal from the Judge-Rapporteur, the General Court (Seventh Chamber) decided to open the oral part of the procedure and, by way of measures of organisation of procedure pursuant to Article 89(3) of the Rules of Procedure, put questions to the parties. The parties complied with that request within the prescribed period.

31

The parties presented oral argument and set out their answers to the questions put by the Court during the hearing on 27 April 2017.

32

The applicants, in the light of the clarifications provided in PLGK’s reply and in the response of the municipality of Gdynia to the measures of organisation of procedure, claim that the Court should:

33

The Commission contends that the Court should:

34

The Republic of Poland supports the form of order sought by the applicants.

35

The action is based, in essence, on six pleas in law.

…

41

The sixth plea in law is based, in essence, on an infringement of essential procedural requirements, breach of the procedural rules as well as of the principles of good administration, protection of legitimate expectations and respect for the rights of the defence.

42

The Court considers it appropriate to examine, in the first place, the sixth plea in law.

…

57

The sixth plea is based, essentially, on three grounds of complaint. First, the applicants contest the absence of publication of the contested decision at the date on which the present action was brought. Second, the applicants consider that the Commission was not entitled to withdraw Decision 2014/883 on the basis of Article 9 of Regulation No 659/1999. Third, the applicants maintain that the Commission ought to have re-opened the formal investigation procedure before adopting the contested decision and ensured compliance with their procedural rights or those of the Republic of Poland.

…

62

As regards the argument that the Commission ought to have opened the formal investigation procedure before adopting the contested decision, and thereby ensured compliance with the procedural rights of the interested parties, it must be noted that, according to the case-law, the procedure for replacing an illegal measure may be resumed at the very point at which the illegality occurred, and the Commission is not required to recommence the procedure by going back further than that precise point (see, to that effect, judgments of 12 November 1998, Spain v Commission, C‑415/96, EU:C:1998:533, paragraph 31; of 3 October 2000, Industrie des poudres sphériques v Council, C‑458/98 P, EU:C:2000:531, paragraph 82; and of 9 July 2008, Alitalia v Commission, T‑301/01, EU:T:2008:262, paragraphs 99 and 142). That case-law relating to the replacement of a measure annulled by the Courts of the European Union also applies, in the absence of any Court annulment of the measure, when the author withdraws and replaces an illegal measure (judgment of 16 March 2016, Frucona Košice v Commission, T‑103/14, EU:T:2016:152, paragraph 61; see also, to that effect, judgment of 12 May 2011, Région Nord-Pas-de-Calais and Communauté d’Agglomération du Douaisis v Commission, T‑267/08 and T‑279/08, EU:T:2011:209, paragraph 83).

63

Nevertheless, the fact that the Commission is not required to recommence the procedure by going back further than the precise point at which the illegality occurred does not, however, mean that it is not, as a matter of principle, required to call on the interested parties to submit their observations before a new decision is adopted.

64

It is true that none of the provisions on the procedure for reviewing State aid reserves a special role, among the interested parties, to the recipient of the aid (judgment of 24 September 2002, Falck and Acciaierie di Bolzano v Commission, C‑74/00 P and C‑75/00 P, EU:C:2002:524, paragraph 83) or to the infra-State body which granted the aid (see, to that effect, order of 5 October 2016, Diputación Foral de Bizkaia v Commission, C‑426/15 P, not published, EU:C:2016:757, paragraph 45, and judgment of 12 May 2011, Région Nord-Pas-de-Calais and Communauté d’agglomération du Douaisis v Commission, T‑267/08 and T‑279/08, EU:T:2011:209, paragraph 71), which implies that the latter could rely on rights as extensive as the rights of defence as such.

65

However, it follows from Article 108(2) TFEU and from Article 1(h) of Regulation No 659/1999 that, during the investigation phase, the Commission must give interested parties, including the undertakings concerned and the infra-State body which granted the aid, an opportunity to submit their comments (see, to that effect, judgments of 8 May 2008, Ferriere Nord v Commission, C‑49/05 P, not published, EU:C:2008:259, paragraph 68, and of 11 December 2008, Commission v Freistaat Sachsen, C‑334/07 P, EU:C:2008:709, paragraph 55). That rule is in the nature of an essential procedural requirement (judgments of 11 December 2008, Commission v Freistaat Sachsen, C‑334/07 P, EU:C:2008:709, paragraph 55, and of 12 September 2007, Olympiaki Aeroporia Ypiresies v Commission, T‑68/03, EU:T:2007:253, paragraph 42). It must allow the interested parties concerned to be involved in the administrative procedure to the extent appropriate in the light of the circumstances of the case (see, to that effect, judgment of 25 June 1998, British Airways and Others v Commission, T‑371/94 and T‑394/94, EU:T:1998:140, paragraph 60). In that context, it has in particular already been held that the Commission was required, where appropriate, to ask interested parties for comments where the legal regimes changed before the Commission took its decision on the basis of the new rules, unless that new legal regime did not contain any substantial change in relation to that previously in force (see judgment of 11 December 2008, Commission v Freistaat Sachsen, C‑334/07 P, EU:C:2008:709, paragraph 56 and the case-law cited).

66

Furthermore, even if it is permissible for the opening decision merely to summarise the relevant issues of fact and law, to include a preliminary assessment as to the aid character of the State measure in question and to set out its doubts as to whether the measure is compatible with the internal market, that decision must give interested parties the opportunity effectively to participate in the formal investigation procedure, during which they will have the opportunity to put forward their arguments (see, to that effect, judgment of 12 May 2011, Région Nord-Pas-de-Calais and Communauté d’agglomération du Douaisis v Commission, T‑267/08 and T‑279/08, EU:T:2011:209, paragraphs 80 and 81). It is necessary, in particular, for the Commission to define sufficiently the framework of its investigation so as not to render meaningless the right of interested parties to put forward their comments (see judgment of 1 July 2009, Operator ARP v Commission, T‑291/06, EU:T:2009:235, paragraph 38 and the case-law cited).

67

In the present case, it must be noted that, in the opening decision, the Commission assessed, provisionally, whether the operating aid was compatible in the light of the Guidelines on national regional aid, taking account of the references made in that regard to paragraphs 27 and 63 of the 2005 Guidelines. In particular, the Commission noted that the Gdynia-Kosakowo airport was located in a region facing a difficult economic situation covered by the derogation set out in Article 107(3)(a) TFEU and that it was necessary to determine whether the conditions set out in paragraph 76 of the Guidelines on national regional aid were met (recitals 64 and 65 of the opening decision).

68

In Decision 2014/883, the Commission noted that ‘Gdynia airport is located in an underprivileged region covered by the derogation set out in Article 107(3)(a) of the TFEU’, and that ‘thus, the Commission has to assess whether the operating aid at stake can be considered compatible under the [Guidelines on national regional aid]’ (recital 221 of Decision 2014/883). In application of paragraph 76 of those guidelines to the present case, the Commission found that the operating aid did not comply ‘with the criteria set out in the [Guidelines on national regional aid]’ (recital 228 of Decision 2014/883).

69

As PLGK rightly notes, supported in this regard by the Republic of Poland and the municipality of Gdynia in their responses to the measures of organisation of procedure, the Commission effected, in the contested decision, a change of legal regime in respect of the compatibility of the operating aid.

70

In that regard, in the first place, the Commission’s argument that the change of legal basis used in the contested decision amounts to a new plea in law put forward by PLGK for the first time at the stage of the reply must be rejected. It is clear from the case-law that a plea which may be regarded as amplifying a plea made previously, whether directly or by implication, in the original application must be considered admissible (judgment of 19 May 1983, Verros v Parliament, 306/81, EU:C:1983:143, paragraph 9; see also, to that effect, judgments of 26 April 2007, Alcon v OHIM, C‑412/05 P, EU:C:2007:252, paragraphs 38 to 40, and of 17 July 2008, Campoli v Commission, C‑71/07 P, EU:C:2008:424, paragraph 63). In the present case, the applicants indicated in their application that they should have been given the opportunity to comment on the Commission’s new arguments and new analysis, and that the failure to fulfil obligations alleged on that point amounts, in itself, to a breach of the procedural rules. More specifically, paragraph II.14 of the application, which summarises the pleas put forward in support of the action, is entitled, inter alia, ‘Breach of the procedural rules in the form of the applicants’ right to submit their comments and to express a view’. The argument put forward in PLGK’s reply, which relates specifically to the Commission’s new analysis carried out in the contested decision, amounts therefore to an amplification of the plea raised in the application alleging breach of the procedural rules relating to the applicants’ right to submit comments. Moreover, and in any event, it must be borne in mind that the rule that the Commission must give interested parties the opportunity to submit comments is in the nature of an essential procedural requirement. Therefore, the breach of that essential procedural requirement, which amount to a public order plea, may be raised by the Court of its own motion (see, to that effect, judgments of 7 May 1991, Interhotel v Commission, C‑291/89, EU:C:1991:189, paragraph 14; of 4 April 2017, European Ombudsman v Staelen, C‑337/15 P, EU:C:2017:256, paragraph 85; and of 16 March 2016, Frucona Košice v Commission, T‑103/14, EU:T:2016:152, paragraph 84).

71

In the second place, in the context of the contested decision, the Commission indicated that it would apply the principles set out in the 2005 Guidelines to the illegal investment aid granted to airports before 4 April 2014 — namely the date of application of the 2014 Guidelines — and ‘the principles set out in the 2014 Guidelines to all cases concerning operating aid … to airports, even if the aid was granted before 4 April 2014’ (recital 196 of the contested decision), as was the case here (recital 197 and Article 2 of the contested decision). It follows that the Commission no longer based itself, as it had in the context of the opening decision and Decision 2014/883, on the Guidelines on national regional aid in order to analyse whether the operating aid was compatible with the internal market, but on the principles set out in the 2014 Guidelines.

72

In the third place, as is apparent from the 2014 Guidelines, the Commission indicated expressly that it would ‘not apply the principles set out in the Guidelines on national regional aid for 2007–2013’ and that ‘the Guidelines on regional State aid for 2014-2020 or any future guidelines on regional aid to State aid granted for airport infrastructure’ would not be applied (paragraph 23 of the 2014 Guidelines).

73

In the fourth place, in addition to the change between the Guidelines on national regional aid and the 2014 Guidelines, the Commission also made a change in the derogation analysed in the light of Article 107(3) TFEU. As follows from the opening decision and Decision 2014/883, the Commission framed its position in the context of the ‘derogation set out in Article 107(3)(a) of the TFEU’. Paragraph 76 of the Guidelines on national regional aid states that operating aid can exceptionally be granted in regions benefiting from the derogation laid set out in Article 107(3)(a) TFEU. As is apparent from paragraph 112 of the 2014 Guidelines, the principles of which were applied by the Commission in the contested decision, the compatibility of operating aid is analysed, in that context, ‘pursuant to Article 107(3)(c) [TFEU]’.

74

In the fifth place, the 2014 Guidelines introduce a ‘new approach to the assessment’ of the compatibility of aid to airports concerning, inter alia, ‘operating aid to regional airports’ (paragraph 17(d) of the 2014 Guidelines). That new approach to the assessment appears in Section 5.1.2 of the 2014 Guidelines. This lays down six cumulative conditions, including the first condition analysed by the Commission in paragraph 246 of the contested decision, namely a determination as to whether the aid contributes to a well-defined objective of common interest. That first condition is itself based on three alternative conditions, that is to say, whether the aid increases the mobility of EU citizens and the connectivity of the regions by establishing access points for intra-Union flights, or combats air traffic congestion at major EU hub airports, or facilitates regional development. Two of those three alternative conditions were mentioned by the Commission in recital 246 of the contested decision.

75

The Guidelines on national regional aid provide that operating aid may be granted, ‘[if] it is justified in terms of its contribution to regional development and its nature and [if] its level is proportional to the handicaps it seeks to alleviate’, which the Commission, moreover, noted in recital 222 of Decision 2014/883.

76

While certain criteria laid down in the 2014 Guidelines and the Guidelines on national regional aid may converge, in particular in relation to regional development aid contributions, those criteria are nevertheless, first, more developed in the 2014 Guidelines and, second, inherently different since the 2014 Guidelines specifically cover airports and airlines. Furthermore, it must be noted that, whereas regional aid contribution is an essential condition in the Guidelines on national regional aid, it is merely an alternative condition in the 2014 Guidelines, as the use of the connective ‘or’ in paragraph 113 of those guidelines demonstrates.

77

In the sixth place, it must be stated that the new approach to the assessment of operating aid provided by the 2014 Guidelines seeks in particular to grant a ten-year transition period during which airports, in particular regional airports, may benefit from that aid, provided that the conditions set out in those guidelines are met (see, in particular, paragraphs 13, 14 and 112 of the 2014 Guidelines).

78

In the light of those factors, the view must be taken that the new legal regime applied by the Commission in the contested decision featured substantial changes in comparison with the regime previously in force and taken into account in the opening decision and in Decision 2014/883.

79

In addition, even if the withdrawal of Decision 2014/883 had the effect, as the Commission claims, of leaving the formal investigation procedure open, the interested parties were not in a position to submit their comments since that procedure was once again closed, simultaneously, by the adoption of the contested decision. It must also be noted that the 2014 Guidelines were published on 4 April 2014, that is to say, after Decision 2014/883 had been adopted and, therefore, after the initial closure of the investigation procedure. It follows that, between the time of publication of the 2014 Guidelines and the adoption of the contested decision, the interested parties were not given the opportunity to submit effectively their comments on the applicability and the possible effect of those guidelines, even though those guidelines amounted to a change in legal regime that the Commission decided to apply to the present case.

80

These findings cannot be brought into question by any of the Commission’s other arguments.

81

In particular, it is necessary to reject the Commission’s argument that PLGK did not demonstrate the extent to which the failure to call upon it to comment on the application of the 2014 Guidelines could have had an effect on its legal situation, or the extent to which the opportunity to comment in that regard could have resulted in a different content of the contested decision. The right of interested parties to be given an opportunity to submit their comments is in the nature of a substantive formality, for the purposes of Article 263 TFEU, infringement of which, as established in the present case, results in the annulment of the vitiated measure, without it being necessary to determine the existence of an effect on the party that alleges such an infringement, or ascertain that the outcome of the administrative procedure might have been different (see, to that effect, judgments of 6 April 2000, Commission v ICI, C‑286/95 P, EU:C:2000:188, paragraph 52, and of 8 September 2016, Goldfish and Others v Commission, T‑54/14, EU:T:2016:455, paragraph 47; Opinion of Advocate General Mengozzi in Bensada Benallal, C‑161/15, EU:C:2016:3, point 92). Moreover, and in any event, given the changes carried out in relation to the legal basis of the FEU Treaty (Article 107(3)(a) TFEU, then Article 107(3)(c) TFEU) and the applicable guidelines, which substantially modify the legal regime of the analysis of whether the operating aid is compatible, the effect of the comments which the interested parties might have submitted cannot be prejudged, even if the Commission, in the contested decision, reached an identical conclusion to that of the decision previously in force.

82

As for the fact that the applicants did not submit comments following the opening decision, that is irrelevant for the purpose of determining whether they were able to submit such comments following the withdrawal of Decision 2014/883 and before the adoption of the contested decision.

83

As regards the Commission’s arguments developed in the context of its response to the measures of organisation of procedure, according to which it had not applied ‘new principles’ stemming from the 2014 Guidelines concerning the operating aid, these are essentially based on the fact that, both in Decision 2014/883 and in the contested decision, the Commission took the view that the operating aid was incompatible with the internal market in that the investment aid was itself incompatible with that market. Those arguments seek, however, essentially to claim that the content of the contested decision would have been identical had the interested parties been given notice to submit comments. They must therefore be rejected on the same grounds as those set out in paragraph 81 above.

84

In any event, it must be recalled that, as follows in particular from recitals 196 and 197 of the contested decision, the Commission made clear that it would apply in the present case the principles set out in the 2014 Guidelines in respect of the operating aid. In that context, the Commission expressly referred to the 2014 Guidelines in recital 245 of the contested decision, by indicating that the fact that the operating aid was itself incompatible with the internal market was equally valid ‘under the 2014 Guidelines’. In addition, it applied the first condition of the 2014 Guidelines in recital 246 of the contested decision, that condition differing substantially from the conditions set out in paragraph 76 of the Guidelines on national regional aid (see paragraph 76 above). It must also be pointed out that, as follows from recitals 198 to 202 of the contested decision, the principles stemming from the 2014 Guidelines were applied for the purpose of differentiating funding relating to investment aid from that relating to operating aid.

85

Furthermore, it must be noted that the contested decision contains at the very least an imprecision, which the Commission, moreover, repeats in its response to the measure of organisation of procedure, concerning the legal framework within which the Commission considered that the operating aid was incompatible with the internal market in that the investment aid was itself incompatible with that market. The Commission indicated in recital 245 of the contested decision that that consideration (which appears also in recital 227 of Decision 2014/883), ‘under the 2005 … Guidelines’, was equally valid in the context of the 2014 Guidelines. As follows from recitals 227 and 228 of Decision 2014/883, the Commission’s assessment was carried out in the context of the Guidelines on national regional aid and on the basis of Article 107(3)(a) TFEU. More specifically, the Commission’s consideration, which was, moreover, made for the sake of completeness as the use of the expression ‘[i]n any case’ demonstrates, was placed before the finding set out in recital 228 of Decision 2014/883, according to which ‘[t]herefore, the Commission considers that the operating aid … does not comply with the criteria set out in the [Guidelines on national regional aid]’.

86

In addition, the consideration that the operating aid is incompatible with the internal market in that the investment aid was itself incompatible with that market does not stem from an express condition provided for by the Guidelines on national regional aid or the 2014 Guidelines. It cannot therefore be inferred from those guidelines that the interested parties were in a position to submit their comments in this respect, as the Commission, however, claims, essentially, in its response to the measures of organisation of procedure. It must be added that Decision 2014/883 was withdrawn and the issue is not so much whether the interested parties had been able to submit comments in relation to that decision, but whether they were able to do so within the context of the formal investigation procedure. In the opening decision, the Commission merely indicated that, in principle, operating aid is incompatible with the internal market, except where it meets the conditions set out in the Guidelines on national regional aid, which did not appear to be the case, prima facie, given that Pomerania was already served by Gdańsk airport (introductory section entitled ‘assessment of the measure’ and recitals 63 to 67 of the opening decision).

87

As regards the argument, put forward by the Commission for the first time during the hearing, to the effect that the view that the operating aid was incompatible with the internal market in that the investment aid was itself incompatible with that market follows from an ‘independent’ legal basis stemming from the Treaty, this argument finds no support in the wording of Decision 2014/883 or of the contested decision. Apart from the failure to state reasons to that effect and the lack of precision in the contested decision, the Commission’s finding was made, as indicated previously, in the context of Article 107(3)(a) TFEU and the Guidelines on national regional aid, in respect of Decision 2014/883, and in the context of Article 107(3)(c) TFEU and the 2014 Guidelines, in respect of the contested decision.

88

Finally, with regard to the Commission’s reference to the case which gave rise to the judgment of 18 November 2004, Ferriere Nord v Commission (T‑176/01, EU:T:2004:336), it must be noted that the Court held, in that case, that ‘[t]he principles laid down by the two sets of guidelines [concerned] [were], in the light of [the] grounds, [of the contested decision in that case], substantially identical’. In particular, the two set of guidelines at issue in that case provided for the eligibility of the investments aimed at protecting the environment and contained the same method of calculating the cost eligible for aid (judgment of 18 November 2004, Ferriere Nord v Commission, T‑176/01, EU:T:2004:336, paragraph 77). Furthermore, the reasons given in the decision contested in that case related to the substantially identical conditions set out by the two sets of guidelines. In the present case, as previously indicated, the Guidelines on national regional aid and the 2014 Guidelines are substantially different, in particular as regards the first condition defined by the 2014 Guidelines analysed by the Commission in the contested decision, and give effect, moreover, to a different provision of the FEU Treaty.

89

Having regard to all of those factors, the view must be taken that the Commission failed to fulfil its obligation to enable the interested parties to submit their comments, without it being necessary to determine whether that failure also amounts to a breach of the procedural rules, an infringement of the right to good administration, legitimate expectations and the rights of the defence, invoked by the applicants before the Court. In particular, there is no need to rule on the possibility for the applicants to claim, before the Court, infringement of the Republic of Poland’s rights of defence, which was raised, moreover, in that Member State’s statement in intervention. Similarly, in that context, it is not necessary to determine whether the Commission also failed to fulfil its obligations by not putting the interested parties on notice to submit their comments in respect of the factual changes made in the contested decision.

90

As for the extent of the illegality thus established, it must be noted that, even if the aid at issue comprises, in fact, two types of funding, namely investment aid and operating aid, those two different types of funding were analysed globally by the Commission, which then determined, in particular, that they constituted State aid. Specifically, the Commission held, in recital 191 of the contested decision, that ‘the capital injections granted to [PLGK] constitutes State aid’. In order to reach that conclusion, the Commission, inter alia, applied the market economy investor criterion, without differentiating between the different types of funding. That global analysis is, moreover, reflected in the operative part of the contested decision since the Commission finds, in Article 2(1) of that decision, that ‘the capital injections in favour of [PLGK] between 28 August 2007 and 17 June 2013 constitute State aid which has been unlawfully put into effect by [the Republic of] Poland’. Those capital injections, effected between 28 August 2007 and 17 June 2013, appear in the table in recital 57 of the contested decision, without the Commission drawing any distinction between the amounts allocated for operating aid or for investment aid. Furthermore, Article 3(1) of the contested decision provides that ‘[the Republic of] Poland shall recover the aid referred to in Article 2(1) from the beneficiary’, without, once again, drawing any distinction between the funding relating to investment and the funding relating to operational matters. Finally, the analysis of the compatibility of the investment aid and that of the compatibility of the operating aid were closely linked, a fact which the Commission confirmed in its response to the measures of organisation of procedure. In those conditions, it is impossible to interpret the operative part of the contested decision as covering, in a separable way, investment aid and operating aid. As for the argument, put forward by the Commission during the hearing, that the annulment, in their entirety, of Articles 2 to 5 of the contested decision would go beyond the scope of the plea raised by the applicants, which, it argues, challenges only the operating aid, suffice it to note, in the first place, that the applicants claim that those articles should be annulled, in the second place, that the plea is a matter of public policy, and, in the third place, that the Commission’s argument cannot bring into question the fact that Articles 2 to 5 of the contested decision concern, in an inseparable way, investment aid and operating aid.

91

In the light of the foregoing, the sixth plea in law must be upheld and, consequently, Articles 2 to 5 of the contested decision must be annulled, without it being necessary to examine the other pleas in law relied on in support of the action.

…

On those grounds,

THE GENERAL COURT (Seventh Chamber)

hereby: