On 13 January 2012, two German professors, Moritz Hagenmeyer and Andreas Hahn, filed suit1 against the European Commission in accordance with Article 263 TFEU because the Commission had refused to authorise the plaintiffs’ application for authorisation of a health claim. Four years prior to that, on 11 February 2008, an authorisation had been sought for the claim “The regular consumption of significant amounts of water can significantly reduce the risk of dehydration and concomitant reduction of performance”, which the defendant refused by way of adopting Regulation (EU) No. 1170/2011.2 In due time, the defendant responded to the statement of claim by pleading its inadmissibility, and shortly after, the Council of the European Union filed an application to intervene in support of the defendant. The plaintiffs agreed to the Council’s application for intervention and responded to the defendant’s defence to the statement of claim in May 2012. Both the defendants’ as well as the plaintiffs’ arguments concerning questions of admissibility are presented in the following.