A brief overview of the changing format and mechanics of national party systems suggests that the direct impact of European integration has been severely limited. Although the national party systems as constituted within the European electoral arena may show signs of such an impact, this has as yet failed to spill over into the strictly domestic arena. Two major reasons are suggested to account for this seeming imperviousness of the national party systems. First, the absence of an arena in which parties may compete at European level for executive office, an absence which thereby hinders the development of a European party system as such. Second, the misplaced division of competences associated with the national and European electoral arenas, whereby issues concerning the European political system itself are 233largely excluded from the national political arena to which they properly belong. The study concludes by suggesting that it is through the indirect process of depoliticisation that Europe may exert its greatest impact on national party systems.