Party Group Switching in the European Parliament

Abstract

Party politics in the European Union (EU) is characterized by competition at two different levels. At the national level, political parties contest national, regional, and local elections. At a transnational level, national parties also compete in elections, for seats in the European Parliament (EP), the legislative body of the EU. National political parties remain the basic organizational unit at both the national and European levels, controlling access to European ballots in each member state, representing policy, and organizing election campaigns. National political parties also form the primary constituent units of the party groups in the EP, coming together to form transnational political entities. These EP party groups have considerable influence over office and policy at the European level, and their goals may be either compatible or conflicting with the interests of national member parties (Hix, Noury, and Roland 2007). EP party groups also formulate their own policy positions and seek to control important offices and legislative goods at the European level. Nonetheless, they remain fundamentally conglomerations of national level parties (Kreppel 2004, 977). A key question thus concerns the calculus of affiliation by which national political parties join or switch between EP party groups.