17It is also settled case-law that, in an action under Article 258 TFEU, the letter of formal notice sent by the Commission to the Member State and the reasoned opinion issued by the Commission delimit the subject matter of the dispute, so that it cannot afterwards be extended. The opportunity for the Member State concerned to submit its observations, even if it chooses not to make use of it, is an essential guarantee intended by the Treaty, adherence to which is an essential formal requirement of the procedure for finding that a Member State has failed to fulfil its obligations. Consequently, the reasoned opinion and the action brought by the Commission must be based on the same complaints as those in the letter of formal notice initiating the pre-litigation procedure (judgments of 29 September 1998, Commission v Germany, C‑191/95, EU:C:1998:441, paragraph 55, and of 10 September 2009, Commission v Portugal, C‑457/07, EU:C:2009:531, paragraph 55 and the case-law cited).
Source: EUR-Lex, © European Union, 1998-2026. Reuse authorised under Decision 2011/833/EU.