Why European Integration Increases Leadership Autonomy within Political Parties

Party scholars have been arguing, at least since the 1960s, that party leaders are becoming more autonomous of their parties in respect of decision-making. This article analyses the impact of European integration on the balance of power in the national parties of EU member states. A theoretical model explaining why European integration increases the autonomy of party leadership is presented together with preliminary evidence. The main argument is that European integration consolidates centralization of decision-making through strengthening the agenda-setting powers of party leaders. Centralization and leadership autonomy should be greater in countries with weak parliamentary scrutiny over EU affairs. The level of control by national legislatures is in turn explained by party cohesion on integration. The concluding section presents questions for future research and discusses some of the main challenges national parties face in adapting to European integration.