<p>Abstract copyright UK Data Service and data collection copyright owner.</p>The main aim of the project was to examine the impact of European integration on the organisation of national political parties, and on the balance of power within them. More specifically, the project sought to investigate whether European integration has further empowered party leaderships, and empowered those people within parties who have an expertise and/or specific involvement in European Union (EU) affairs. As yet, little research has examined the impact of the EU on the internal workings of national political parties. The project thus set out to address the lack of attention that political parties have received in this context and sought to provide the firs...