"Ne bis in idem" in State aid control? CJEU quashes Deutsche Post decision (C-77/12 P)

In its Judgment of 24 October 2013 in case C-77/12 P Deutsche Post v Commission, the Court of Justice of the EU quashed a Judgment of the General Court (T-421/07) and (indirectly) questioned a decision taken by the European Commission concerning the State aid granted by Germany to Deutsche Post in the 1990s. The Commission had adopted an initial negative decision in 2002 (ultimately quashed by the CJEU in C-399/08 P) and, following a request by the initial complainants to look into the matter in more detail, it decided to extend the scope of the original investigation in a 'follow-up' enquiry carried out in 2007 (while the GC was still considering the legality of the original negative decision).
Germany challenged the decision of the European Commission on the general basis that, contrary to its allegations, this 'follow-up' enquiry would alter the legal effects of the initial decision (now annulled) and that such an enforcement strategy would be against the most fundamental principles of due process and good administration.
The GC (T-421/07) took no issue with the opening of the 'follow-up' investigation, as it considered that such a decision did not alter the legal standing of the State aid measures under investigation, since they had already been flagged as potentially illegal in the initial decision to open an investigation that the Commission adopted in 1999 (and regardless of the fact that they were not included in the original negative decision of 2002). In even more controversial terms, the GC brushed aside the argument that the annulment of the 2002 negative decision should also be taken into consideration in order to bar any 'follow-up' investigation that ultimately had the same origin. As the CJEU summarises,
In addition, the [General] Court observed in paragraphs 77 and 79 of the contested judgment, that this conclusion is not undermined by the judgment in Deutsche Post / Commission [...]. Indeed, this decision did not rule on the question whether the formal investigation procedure initiated in 1999 in respect of the disputed measures has been closed. The Court further considersed that this decision had the effect of retroactively eliminating the 2002 negative decision, so that "this decision can in no way affect the conclusion that the 2002 [negative] decision had no impact on the existence of any independent legal effects generated by [the contested decision] (C-77/12 P at para 37, own translation from French).
On the basis of those considerations, the GC considered that the 2007 decision to carry out a 'follow-up enquiry' was not open to an annulment action under Article 263(4) TFEU and, consequently, dismissed Deutsche Post's challenge. The CJEU has taken a different view.
I find it interesting to stress that the CJEU has argued that:
52 As regards, in particular, the binding legal effects of a decision to initiate the procedure provided for in Article [108], paragraph 2 [TFEU] with respect to a measure running and qualified as new aid, such a decision necessarily changes the legal status of the measure, as well as the legal position of the beneficiaries, particularly in regard to its implementation. After the adoption of such a decision, there is at least a significant doubt about the legality of this measure, which must lead the Member State to suspend the payment, since the opening of the procedure laid down in Article [108], paragraph 2 [TFEU] excludes an immediate decision on the compatibility with the common market that would allow for the regular execution of the measure. Such a decision could be invoked before a national court called upon to draw all the consequences of the violation of Article [108], paragraph 3, last sentence, [TFEU]. Finally, it is likely to lead beneficiaries of the measure to refuse in any event new payments or to provision the necessary funds for any subsequent repayments. The beneficiaries will also be affected in their relations with other agents, which will take into consideration the weakened legal and financial situation of the former (see judgment of 9 October 2001, Italy / Commission, C-400/99, Rec . P. I- 7303, paragraph 59).
53 It should be added that […] such a decision to open an investigation with respect to a measure that the Commission describes as new aid is not simply a preparatory step in that it has independent legal effects, particularly with regard to the suspension of the measure under consideration.
54 In this case, it should be noted that […] in the contested decision, the Commission qualified as new aid the transfer payments made by DB-Telekom and the system of public guarantees. Furthermore, as regards the public pension fund, this institution has expressed its doubts about the extent to which this funding granted an economic advantage to [Deutsche Post]. The Commission also pointed out […] that Germany was under the obligation to suspend the measures challenged by the decision.
55 It follows that the 2007 opening decision is an act that is likely to affect the interests of [Deutsche Post] by altering its legal status and, therefore, it meets all the elements of an act within the meaning of Article [263 TFEU].
56 Contrary to what the Court considered […] that finding is not challenged by the existence of the decision to open an investigation in 1999, by which the Commission opened the procedure laid down in Article [108], paragraph 2 [TFEU] in respect of a series of measures being implemented.
57 Indeed, it is clear that, in any event, the Commission, by its negative decision of 2002, closed the formal investigation procedure in 1999.
58 In this regard, it should be noted that the Commission dealt in its negative decision of 2002, of all the measures challenged by the opening 1999 decision, as argued rightly [Deutsche Post] (C-77/12 P at paras 52-58, own translation from French, emphasis added).

Even if this may not be the end of the story in this particular case, which has been sent back to the GC, I think that the principle established by the CJEU could be read as a sort of 'ne bis in idem' in the area of State aid enforcement. Once a measure has been analysed and the Commission reaches a final decision, then the same measure should not be subjected to additional enquiries and no new findings of incompatibility should be acceptable.
In maybe more blunt terms, the Commission has one shot (and only one) at each controversial State aid measure, in order to protect legal certainty and as an (implicit) requirement of the principle of good administration.
Overall, I would consider such a general principle a positive development in EU State aid law. It remains to be seen, however, whether this reasoning is only case-specific or the CJEU is willing to flesh out such a general principle in even clearer terms, should the opportunity arise in the future.