General principles of EU Law as evidence of the development of a Common European Legal Thinking: the example of the proportionality principle (from the Italian perspective)

The reference to general principles of law allows the EU judges to fill in the many gaps in the EU legal system which are inevitably related to the fact that the EU still follows the principle of conferral. So that the reference to the laws of the Member States and, more generally, to rules "others" than the EU written sources is indeed a necessary part of the way of operating and even of “being” of the EU Courts . This constant reference of the EU judge, in its judicial review activity, to rules “others” than those contained in EU written sources has transformed it into the most powerful vehicle of diffusion of principles and models of administrative action . A proven evidence of this is the principle of proportionality, which has rapidly extended its influence within national legal orders of the Member States, also for cases without any direct relevance to EU law. The best evidence of this phenomenon is the domestic jurisprudence of the Italian Administrative Courts in the years 2000: which is characterized by a wide application of the principle of proportionality, both by the Regional Administrative Courts and by the Council of State . The principle of proportionality has enriched substantially the instruments of judicial review available to the administrative judge in order to operate its control on the legality of administrative action. It is, in fact, thanks to this tool that the administrative judge can now effectively review administrative measures with respect to which the exercise of public power reveals as exuberant in relationship to what would have been enough for the public administration to pursue the public interest entrusted to his care .