Seminar paper from the year 2003 in the subject Politics - International Politics - Topic: European Union, grade: 1.5, University of Bern, language: English, abstract: Abstract There is a broad consensus that courts play a significant role in the process of European integration. By giving rulings on preliminary references the European Court of Justice (ECJ) asserted the two central principles "supremacy" and "direct effect," which transformed the treaty into something like a constitution. The interaction between national judges and the ECJ through the preliminary reference procedure eased this process, but not all member states used this possibility in the same degree. Whereas German, Italian and Austrian judges widely used this procedure in recent years, other countries like France, Ireland, Spain and Portugal hardly did. In this empirical analysis, which is based on data covering all current member states, I try to find some general explanations and fundamental aspects of variance in preliminary references by applying Europeanization and political-institutional theory.