Europarties and the Politics of Treaty Reform: Ascendance, Capacity, Locus

Constitutional politics at European level has resulted in wide-ranging Treaty reforms over the past four decades, conventionally examined through the lens of intergovernmentalism. But what has been the role of transnational political parties in these processes? This chapter considers the impact of the Europarties and especially the European People’s Party but also the Party of European Socialists in Treaty reforms. It suggests that their impact can be explained in general terms by three factors: (1) the partisan composition of the European Council; (2) the cohesion and mobilization of Europarties; and (3) the choice of venue for deliberations and negotiations of Treaty changes. The chapter explores the influence of these factors empirically through illustrative evidence. It concludes that while the conditions for Europarty influence are demanding, the successive Treaties are to a considerable extent the result of transnational party-political contributions.