This book explores the European stances of three of Northern Ireland’s political parties, culminating in one of the most tumultuous episodes in recent UK, Irish, and European politics.

It examines how and why Sinn Féin, the Ulster Unionist Party (UUP), and the Democratic Unionist Party (DUP) developed their respective positions on Europe and reveals that each party adopted approaches to the EU that do not neatly align with expectations about the influence of party voters and members. To make sense of this, the book offers an alternative account grounded in historical institutionalism, incorporating additional factors that capture the transnational nature of Northern Ireland’s politics. It stresses the importance of understanding how participation in different political institutions over time has shaped these parties’ behaviour. It argues that an institutional analysis of party politics in Northern Ireland can add valuable insights, including into the tumultuous Brexit period, and demonstrates that the ways in which these parties approached European integration are key to understanding the wider story of the UK and Ireland’s relationship with the EU.

This book will be of key interest to students and scholars of Irish politics and Irish studies, British politics, European politics and integration, and party politics.