Overview of the Doctrine of Ultra Vires from the Perspective of the German Federal Constitutional Court and the Polish Constitutional Court

European Union law is based on a number of principles of application, such as the principle of primacy or the principle of conferral. Over the years of this project's existence, we have witnessed Member States being excessively cautious on the subject of the primacy of European Union law. Among these Member States is Germany, which has for years shown its vigilance towards the proceedings and acts of the European Union, whether through the well-known Solange judgement or the recent judgment in the PSPP case. The Federal Constitutional Court has thus created a controlling competence vis-à-vis the bodies and institutions of the European Union by which it seeks to ensure that its standard of constitutional protection is maintained. The present article focuses on the development of the ultra vires review competence and it analyses the manner in which it has been exercised. It also focuses on the use of the ultra vires review by Poland in the K 3/21 case, which has resonated with both the professional and non-professional public. The article also aims to compare the judgment in the PSPP case and the judgment in K 3/21 and to assess whether the ultra vires review was properly activated by the Polish Constitutional Court.