It has been recognised on numerous occasions by the case-law of the Court of Justice, initially in the Hauer judgment (13 December 1979, [1979] ECR 3727).
Is iomaí uair a aithníodh i gcásdlí na Cúirte Breithiúnais é, agus is i mbreithiúnas Hauer a aithníodh den chéad uair é (13 Nollaig 1979 [1979] ECR 3727).