The retroactivity of European law

Article 297(1) TFEU states that “Legislative acts shall be published in the Official Journal of the European Union. They shall enter into force on the date specified therein or, in the absence of such a date, on the twentieth day following their publication.”

A judgment of 13/02/2019 of the Court of Justice of the European Union confirms the absence of retroactivity in points 36-37, specifying that the principle of legal certainty precludes an act of the Union from having its starting point set before its publication, unless the text of the Regulation provides that it applies to previous situations.

A ruling by the French Court of Cassation (cass.com. 22/10/2002 No. 00-10.715), ruling on the application of a European Regulation, specifies that the principle of legal certainty precludes a (European) Regulation from being applied retroactively to facts that arose under the previous regime.

The Charter of Fundamental Rights of the European Union contains a number of provisions, including Article 49, which states that “No one shall be convicted of an act or omission which did not constitute an offense under national or international law at the time it was committed.” 

Article 7 of the European Convention on Human Rights states that “No one shall be convicted of an act or omission which did not constitute an offense under national or international law at the time it was committed.”

Thierry Clerc – 06/08/2025