Med forbehold af den kompetence, der er tillagt Den Europæiske Unions Domstol ved traktaterne, er de tvister, i hvilke Unionen er part, ikke af den grund unddraget de nationale dømmende myndigheders kompetence.
Save where jurisdiction is conferred on the Court of Justice of the European Union by the Treaties, disputes to which the Union is a party shall not on that ground be excluded from the jurisdiction of the courts or tribunals of the Member States.