C-850/25

ORDER OF THE COURT (Chamber determining whether appeals may proceed) 9 June 2026 (*) ( Appeal – Regulation (EU) 2017/2195 – European Union Agency for the Cooperation of Energy Regulators (ACER) – Determination as to whether appeals should be allowed to proceed – Article 170b of the Rules of Procedure of the Court of Justice – Request failing to demonstrate that an issue is significant with respect to the unity, consistency or development of EU law – Refusal to allow the appeal to proceed ) In Case C‑850/25 P, APPEAL under Article 56 of the Statute of the Court of Justice of the European Union, brought on 18 December 2025, Swissgrid AG, established in Aarau (Switzerland), represented by P. De Baere, A. Kavoosi, P. L’Ecluse, V. Lefever and K. T’Syen, avocats, appellant, the other parties to the proceedings being: European Union Agency for the Cooperation of Energy Regulators (ACER), defendant at first instance, European Commission, intervener at first instance, THE COURT (Chamber determining whether appeals may proceed), composed of T. von Danwitz, Vice-President of the Court, O. Spineanu-Matei and N. Fenger (Rapporteur), Judges, Registrar: A. Calot Escobar, having regard to the proposal from the Judge-Rapporteur and after hearing the Advocate General, M. Szpunar, makes the following Order 1        By its appeal, Swissgrid AG asks the Court of Justice to set aside the judgment of the General Court of the European Union of 8 October 2025, Swissgrid v ACER (T‑557/23, ‘the contested judgment’, EU:T:2025:942), by which the General Court dismissed its action for the annulment of Decision A-007-2022 of the Board of Appeal of the European Union Agency for the Cooperation of Energy Regulators (ACER) of 29 June 2023 dismissing as inadmissible the appeal against ACER’s Decision 14/2022 of 30 September 2022 (‘the decision at issue’). The request that the appeal be allowed to proceed 2        Under the first paragraph of Article 58a of the Statute of the Court of Justice of the European Union, an appeal brought against a decision of the General Court concerning a decision of an independent board of appeal of ACER is not to proceed unless the Court of Justice first decides that it should be allowed to do so. 3        In accordance with the third paragraph of Article 58a of the Statute of the Court of Justice of the European Union, an appeal is to be allowed to proceed, wholly or in part, in accordance with the detailed rules set out in the Rules of Procedure of the Court of Justice, where it raises an issue that is significant with respect to the unity, consistency or development of EU law. 4        Article 170a(1) of the Rules of Procedure provides that, in the situations referred to in the first paragraph of Article 58a of the Statute of the Court of Justice of the European Union, the appellant is to annex to the appeal a request that the appeal be allowed to proceed, setting out the issue raised by the appeal that is significant with respect to the unity, consistency or development of EU law and containing all the information necessary to enable the Court of Justice to rule on that request. 5        In accordance with Article 170b(1) and (3) of the Rules of Procedure, the Court’s decision on the request that the appeal be allowed to proceed is to be taken as soon as possible in the form of a reasoned order. Arguments of the appellant 6        In support of its request that the appeal be allowed to proceed, the appellant relies on six grounds of appeal, by which it submits that its appeal raises issues that are significant with respect to the unity, consistency and development of EU law. 7        By its first and fifth grounds of appeal, the appellant challenges the General Court’s interpretation of Article 1(6) and (7) of Commission Regulation (EU) 2017/2195 of 23 November 2017 establishing a guideline on electricity balancing (OJ 2017 L 312, p. 6). 8        By the first ground of appeal, the appellant submits, in essence, first, that the General Court introduced an additional substantive condition governing its participation in the European platform for the exchange of balancing energy from frequency restoration reserves with manual activation, not provided for in Article 1(6) of Regulation 2017/2195. Second, the General Court undermined the fundamental objective of system security referred to in that provision. Third, it misinterpreted the second condition for the participation of transmission system operators (TSOs) operating in Switzerland in the European platforms for the exchange of standard products for balancing energy (‘the balancing platforms’), thus infringing that provision. Fourth, it misinterpreted Article 1(6) of Regulation 2017/2195 in referring to the objective of the creation of an internal market. Fifth, it failed to observe the principle nemo auditur propriam turpitudinem allegans by allowing ACER to rely on unlawful conduct on the part of the European Commission. Sixth and lastly, it misinterpreted the Agreement between the European Economic Community and the Swiss Confederation of 22 July 1972 (OJ, English Special Edition: Series I Volume 1972, p. 191; ‘the Free Trade Agreement’). 9        By the fifth ground of appeal, the appellant alleges a failure to state reasons in the contested judgment. The appellant contends that the General Court contradicted itself in its interpretation of Article 1(6) and (7) of Regulation 2017/2195. Its interpretation also renders meaningless the conditions laid down in Article 1(6) of that regulation. Lastly, it interpreted inconsistently the condition laid down in Article 1(7) of that regulation. 10      In order to establish the significance of the issues raised by those grounds of appeal for the purposes of Article 58a of the Statute of the Court of Justice of the European Union, the appellant submits that its appeal follows the judgment of 13 February 2025, Swissgrid v Commission (C‑121/23 P, EU:C:2025:83), by which the Court of Justice, on the ground that the General Court had incorrectly applied the criteria for the admissibility of the action after analysing the substance of Article 1(6) and (7) of Regulation 2017/2195, set aside the order of the General Court of 21 December 2022, Swissgrid v Commission (T‑127/21, EU:T:2022:868). The appellant submits that, since the General Court confirmed the inadmissibility of the action it had brought on the basis of those provisions, there is a need for the Court of Justice to provide guidance on their interpretation, particularly in the light of the objective of system security. 11      By its second ground of appeal, the appellant submits that the General Court erred in law by confirming the application, in the present case, by the ACER Board of Appeal of Article 28(1) of Regulation (EU) 2019/942 of the European Parliament and of the Council of 5 June 2019 establishing a European Union Agency for the Cooperation of Energy Regulators (OJ 2019 L 158, p. 22), relating to the conditions of admissibility of an appeal against an individual decision adopted by ACER. According to the appellant, the second ground of appeal raises the issue as to whether the decision at issue affects its legal position, in so far as that decision amends the definition of the concept of ‘member TSO’ laid down in Article 2(1)(l) of the implementation framework for the European platform for the exchange of balancing energy from frequency restoration reserves with manual activation. 12      Moreover, according to the appellant, in a European Union founded on the rule of law, persons affected by legally binding EU acts governing their participation in electricity cooperation mechanisms should be able to challenge those acts. In particular, in the context of recent changes in the scope of such cooperation mechanisms, the second ground of appeal raises a recurring and unresolved issue of admissibility for those persons. 13      By its third ground of appeal, the appellant argues, in essence, that the General Court erred in law in rejecting the plea of illegality raised in respect of Regulation 2017/2195. First, by failing to examine the two cumulative conditions governing the exercise of the Commission’s implementing powers, the General Court misapplied the test for determining whether the Commission had the power to adopt Article 1(6) and (7) of that regulation. Second, the General Court departed from the case-law of the Court of Justice, in particular the judgment of 28 July 2016, Council v Commission (C‑660/13, EU:C:2016:616), in holding that the conditions for the Swiss Confederation’s participation in that regulation could be adopted by means of a delegated act, whereas setting such conditions is a policy choice. 14      According to the appellant, that ground raises issues concerning fundamental constitutional principles of EU law, namely the principle of conferral, the distribution of powers between institutions, institutional balance and the consistency of the case-law of the Court of Justice. 15      By its fourth ground of appeal, the appellant claims that the General Court misapplied the Free Trade Agreement. According to the appellant, the General Court erred in law in holding that the appellant’s exclusion from the balancing platforms effected by Regulation 2017/2195 did not constitute an infringement of that agreement. 16      The significance of the issue raised by that ground, namely whether such an exclusion constitutes a quantitative restriction on imports of electrical energy, contrary to the Free Trade Agreement, stems from two factors. First, the General Court’s reasoning deprives the Free Trade Agreement of any substance in breach of the obligation to give effect to such agreements within the EU legal order, particularly in the light of Article 3(5) TEU. Second, the General Court failed to follow the case-law arising from the judgment of 3 June 2008, Intertanko and Others (C‑308/06, EU:C:2008:312), which requires, when the validity of a measure of secondary EU legislation is challenged in the light of an international agreement, the EU Courts to examine whether that agreement produces direct effects. 17      By its sixth ground of appeal, the appellant submits that the General Court erred in law in holding, first, that Regulation 2017/2195 laid down a rule of principle excluding third-country TSOs, including the appellant, from participating in the balancing platforms and, second, that Article 1(6) and (7) of that regulation established an exception to that rule. 18      The significance of the issue raised by that ground relates, first, to the incompatibility of that rule with the fundamental principle that what is not prohibited is permitted, and, second, to the fact that that rule deprives pre-existing cooperation arrangements involving EU TSOs and the appellant of legal effects, contrary to the principle of legal certainty. 19      The appellant claims, in the alternative, that Article 58a of the Statute of the Court of Justice of the European Union and Article 170a of the Rules of Procedure should be declared inapplicable in the present case and that its appeal should be examined by the Court of Justice without being subject to the present procedure for prior determination as to whether it should be allowed to proceed. 20      It submits that, although the decision at issue was adopted by the ACER Board of Appeal, a body referred to in the first paragraph of Article 58a of the Statute of the Court of Justice of the European Union, that board did not rule as an appellate body, but as an administrative body of first instance. The General Court was therefore the first court before which the case was brought. Findings of the Court 21      As regards, first of all, the line of argument summarised in paragraphs 19 and 20 of the present order, as recalled in paragraph 2 above, an appeal brought against a decision of the General Court concerning a decision of an independent board of appeal of ACER is, under the first paragraph of Article 58a of the Statute of the Court of Justice of the European Union, not to proceed unless the Court of Justice first decides that it should be allowed to do so. 22      In that regard, it should be observed that that provision applies, without exception, to all decisions of the General Court concerning a decision of an independent board of appeal of ACER. In the present case, it is common ground that the decision at issue was adopted by the Board of Appeal of ACER, which is an independent board of appeal within the meaning of that provision. 23      Accordingly, Article 58a of the Statute of the Court of Justice of the European Union and Article 170a of the Rules of Procedure are applicable in the present case. 24      Next, it must be recalled that it is for the appellant to demonstrate that the issues raised by its appeal are significant with respect to the unity, consistency or development of EU law (orders of 10 December 2021, EUIPO v The KaiKai Company Jaeger Wichmann, C‑382/21 P, EU:C:2021:1050, paragraph 20, and of 24 March 2026, Capella v EUIPO, C‑766/25 P, EU:C:2026:276, paragraph 15). 25      Furthermore, as is apparent from the third paragraph of Article 58a of the Statute of the Court of Justice of the European Union, read together with Article 170a(1) and Article 170b(4) of the Rules of Procedure, the request that an appeal be allowed to proceed must contain all the information necessary to enable the Court to give a ruling on whether the appeal should be allowed to proceed and to specify, where the appeal is allowed to proceed in part, the pleas in law or parts of the appeal to which the response must relate. Given that the objective of the mechanism provided for in Article 58a of that statute whereby the Court determines whether an appeal should be allowed to proceed is to restrict review by the Court to issues that are significant with respect to the unity, consistency or development of EU law, only grounds of appeal that raise such issues and that are established by the appellant are to be examined by the Court in an appeal (orders of 10 December 2021, EUIPO v The KaiKai Company Jaeger Wichmann, C‑382/21 P, EU:C:2021:1050, paragraph 21, and of 24 March 2026, Capella v EUIPO, C‑766/25 P, EU:C:2026:276, paragraph 16). 26      Accordingly, a request that an appeal be allowed to proceed must, in any event, set out clearly and in detail the grounds on which the appeal is based, identify with equal clarity and detail the issue of law raised by each ground of appeal, specify whether that issue is significant with respect to the unity, consistency or development of EU law and set out the specific reasons why that issue is significant according to that criterion. As regards, in particular, the grounds of appeal, the request that an appeal be allowed to proceed must specify the provision of EU law or the case-law that has been infringed by the judgment or order under appeal, explain succinctly the nature of the error of law allegedly committed by the General Court, and indicate to what extent that error had an effect on the outcome of the judgment or order under appeal. Where the error of law relied on results from an infringement of the case-law, the request that the appeal be allowed to proceed must explain, in a succinct but clear and precise manner, first, where the alleged contradiction lies, by identifying the paragraphs of the judgment or order under appeal which the appellant is calling into question as well as those of the ruling of the Court of Justice or the General Court alleged to have been infringed, and, second, the concrete reasons why such a contradiction raises an issue that is significant with respect to the unity, consistency or development of EU law (orders of 10 December 2021, EUIPO v The KaiKai Company Jaeger Wichmann, C‑382/21 P, EU:C:2021:1050, paragraph 22, and of 24 March 2026, Capella v EUIPO, C‑766/25 P, EU:C:2026:276, paragraph 17). 27      A request that an appeal be allowed to proceed which does not contain the information mentioned in the preceding paragraph cannot be capable of demonstrating that the appeal raises an issue that is significant with respect to the unity, consistency or development of EU law that justifies the appeal being allowed to proceed (orders of 24 October 2019, Porsche v EUIPO, C‑613/19 P, EU:C:2019:905, paragraph 16, and of 24 March 2026, Capella v EUIPO, C‑766/25 P, EU:C:2026:276, paragraph 18). 28      In the first place, by the first and fifth grounds of appeal, summarised in paragraphs 7 to 10 above, the appellant calls into question the interpretation of Article 1(6) and (7) of Regulation 2017/2195, concerning the participation in the balancing platforms of TSOs operating in Switzerland. 29      Apart from the fact that the issues of law raised by those grounds of appeal are not set out clearly and in detail in the appellant’s arguments, it must be pointed out that although the appellant refers to the judgment of 13 February 2025, Swissgrid v Commission (C‑121/23 P, EU:C:2025:83), and claims, in essence, that, in that judgment, the Court of Justice cast doubt on the interpretation of Article 1(6) and (7) of Regulation 2017/2195 arrived at by the General Court in the contested judgment, such a claim is not sufficient to establish that an appeal raises an issue that is significant with respect to the unity, consistency or development of EU law. To that end, the appellant must comply with all the requirements set out in paragraph 26 above (see, to that effect, order of 17 October 2023, Kaminski v EUIPO, C‑406/23 P, EU:C:2023:787, paragraph 20). 30      Regarding, more specifically, the fifth ground of appeal alleging a failure by the General Court to state reasons, it must be borne in mind that while an absence of or an inadequate statement of reasons constitutes an error of law which may be invoked in the context of an appeal, the determination as to whether the appeal is allowed to proceed remains subject to specific conditions consisting, for the appellant, in demonstrating, as stated in paragraph 26 of the present order, that the appeal raises one or more issues that are significant with respect to the unity, consistency or development of EU law (see, to that effect, order of 15 July 2025, Qozgar v EUIPO, C‑35/25 P, EU:C:2025:582, paragraph 21 and the case-law cited). In order to demonstrate that that is the case, it is necessary to establish both the existence and the significance of such issues by means of concrete evidence specific to the particular case, and not simply by arguments of a general nature. However, the appellant does not demonstrate to the requisite legal standard how the alleged failure to state reasons in the contested judgment raises an issue that is significant with respect to the unity, consistency or development of EU law. 31      In the second place, by its second ground of appeal, summarised in paragraphs 11 and 12 above, the appellant claims, first of all, that the issues of admissibility raised by the application of the electricity cooperation mechanism are of a recurring nature, contending that there is a likelihood of further ACER decisions similar to that at issue in the present case. In that regard, suffice it to recall that the Court of Justice has previously held that the fact that an issue may concern a large number of cases cannot be regarded as necessarily relevant or, in any event, sufficient to establish that that issue is significant with respect to the unity, consistency or development of EU law (order of 1 October 2025, Boehringer Ingelheim Pharma v EUIPO, C‑44/25 P, EU:C:2025:740, paragraph 24). 32      Next, as regards the successive amendments to the scope of the implementation frameworks for the cooperation mechanisms, the appellant does not explain how the fact that the legislative framework has evolved establishes the significance of that issue. 33      Lastly, the appellant argues, in essence, that the right of appeal is of importance in a European Union founded on the rule of law, merely invoking the right of appeal and the rule of law without providing any further particulars. 34      In that regard, it is sufficient to recall that, in accordance with the burden of proof which lies with an appellant requesting that an appeal be allowed to proceed, the appellant must demonstrate that, independently of the issues of law invoked in its appeal, the appeal raises one or more issues that are significant with respect to the unity, consistency or development of EU law, the scope of that criterion going beyond the judgment under appeal and, ultimately, its appeal. In order to demonstrate that that is the case, it is necessary to establish both the existence and significance of such issues by means of concrete evidence specific to the particular case, and not simply by arguments of a general nature (orders of 10 December 2021, EUIPO v The KaiKai Company Jaeger Wichmann, C‑382/21 P, EU:C:2021:1050, paragraphs 27 and 28, and of 3 March 2026, DJO v EUIPO, C‑702/25 P, EU:C:2026:143, paragraph 16). 35      In the third place, as regards the third ground of appeal, summarised in paragraphs 13 and 14 above, it should be noted, first, that, without prejudice to the important place occupied within the EU legal order by the principle of conferral, the distribution of powers between institutions, institutional balance and the consistency of the Court’s case-law as fundamental constitutional principles of EU law, merely invoking them is not sufficient to satisfy the conditions set out in paragraph 26 above. In order to demonstrate the significance of the issue raised by that ground of appeal, the appellant merely cites those principles. 36      Second, although the appellant argues that there is a contradiction between certain grounds of the contested judgment and the judgment of 28 July 2016, Council v Commission (C‑660/13, EU:C:2016:616), such a claim is not, in itself, sufficient to establish, in accordance with the burden of proof which lies with the person requesting that an appeal be allowed to proceed, that that appeal raises an issue that is significant with respect to the unity, consistency and development of EU law. As recalled in paragraph 29 above, the appellant must, for that purpose, comply with all the requirements set out in paragraph 26 above. However, the appellant, apart from failing to provide any indication as to the similarity between the situations referred to in the contested judgment and the judgment of the Court of Justice cited above, also fails to explain, with sufficient precision and clarity, the reasons why the alleged contradiction between the General Court’s assessments in the contested judgment and that judgment of the Court of Justice raises an issue that is significant with respect to the unity, consistency or development of EU law. 37      In the fourth place, although, by its fourth and sixth grounds of appeal, summarised in paragraphs 15 to 18 above, the appellant identifies the errors of law allegedly made by the General Court, it does not, in any event, demonstrate how such errors of law, even if established, raise issues that are significant with respect to the unity, consistency or development of EU law so as to justify the appeal being allowed to proceed. The appellant merely alleges infringement of Article 3(5) TEU, breach of the principle that what is not prohibited is permitted, and breach of the principle of legal certainty, without providing further details. 38      In addition, in so far as the appellant alleges that the General Court failed to comply with the obligations identified by the Court of Justice in the judgment of 3 June 2008, Intertanko and Others (C‑308/06, EU:C:2008:312), suffice it to state that the appellant does not specify the reasons why the alleged contradiction between the General Court’s assessments and the case-law of the Court of Justice raises an issue that is significant with respect to the unity, consistency or development of EU law, nor does it provide any indication as to the similarity of the situations referred to in the case-law that was allegedly disregarded, which would establish the existence of the contradictions alleged. 39      In those circumstances, the request submitted by the appellant that the appeal be allowed to proceed is not capable of establishing that the appeal raises an issue that is significant with respect to the unity, consistency or development of EU law. 40      In the light of all the foregoing considerations, the appeal should not be allowed to proceed. Costs 41      Under Article 137 of the Rules of Procedure, applicable to proceedings on appeal pursuant to Article 184(1) of those rules, a decision as to costs is to be given in the order which closes the proceedings. 42      Since the present order was adopted before the appeal was served on the other party to the proceedings and, therefore, before it could have incurred costs, it is appropriate to decide that the appellant is to bear its own costs. On those grounds, the Court (Chamber determining whether appeals may proceed) hereby orders: 1.      The appeal is not allowed to proceed. 2.      Swissgrid AG shall bear its own costs. Luxembourg, 9 June 2026. A. Calot Escobar T. von Danwitz Registrar President of the Chamber determining whether appeals may proceed *      Language of the case: English.