While the consequences of becoming an EU Member State for national policies are usually the core concern of pre-membership debates and of post-accession assessments, studies of the effects of European integration on the political systems of the Member States have so far been less numerous. Among the new EU members, which are ideal cases for studying domestic accession effects, Austria is a particularly challenging case in terms of top-down impact on the national political system. A number of specific precautions were taken in order to protect typical features of the national political system (notably the traditional roles of parliament, Länder and social partners) from being eroded in the multi-level system. The basic research question of this article is whether or not these measures were actually successful. How ‘sticky’ is the EU upon closer inspection, i.e. how pervasive are its effects on adverse national structures? Can national measures, even at the constitutional level, outweigh specific consequences of participating in Euro-politics? If not 9as the Austrian case indicates), why not? The conclusions distinguish specific Austrian variables from generalizable ones and discuss the findings in the light of the existing literature.