Il principio della res iudicata e l’effettività della tutela dei diritti garantiti dalle fonti di diritto UE: verso nuovi sviluppi di una antica questione?

According to a well-established case-law of the Court of Justice of the EU, the principle of res iudicata falls within the procedural autonomy of the Member States and must be exercised in compliance with the principles of equivalence and effectiveness. Another relevant limit to the national procedural autonomy stems from the right to effective judicial protection, as a general principle of EU law which is now enshrined in Art. 47 of the Charter of Fundamental Rights of the EU. The paper discusses the case-law of the Court of Justice on the limitations imposed by EU law on the authority of res judicata of national judgments which are incompatible with EU law. After examining the role played by the principles of equivalence and effectiveness, the analysis focuses on the case-law on consumer protection against unfair contracts in which the Court has meaningfully limited the effect and the scope of the res judicata in order to ensure the (consumers’) effective judicial protection, as guaranteed by Art. 47 of the Charter and the relevant secondary law.