The Survival of Cross-Border Parties in Western Europe. A Comparative Case Study

This paper examines the emergence and organisational dynamics of cross-border political parties in Europe, challenging the conventional assumption that parties operate within bounded national arenas. It defines cross-border parties as organisations that compete in elections and maintain organisational links across at least two neighbouring states within the same territorial community. Despite the significant organisational and coordination costs involved in operating across distinct political and legal contexts, some of these parties endure while others fail to consolidate. What explains this variation? The paper argues that the survival of cross-border parties depends on how they manage a fundamental tension between integration and autonomy. While central party actors require integration to ensure coherence, coordination, and resource sharing, territorial branches must retain sufficient autonomy to adapt to different institutional and electoral environments. This tension is conceptualised through a principal–agent framework, highlighting how the balance between central control and local discretion shapes organisational sustainability over time. Empirically, the paper adopts a small-N comparative design, analysing four Western European cases: Sinn Féin, the Basque Nationalist Party (PNV), Esquerra Republicana de Catalunya (ERC), and Forum voor Democratie (FvD). Drawing on party documents, secondary literature, and original interviews conducted between 2025 and 2026, it compares organisational structures, coordination mechanisms, and resource flows across cases. The paper makes three contributions: it conceptualises cross-border parties as a distinct type of party organisation; it extends theories of multilevel and territorial party politics beyond the state; and it identifies the organisational mechanisms that underpin the endurance or failure of cross-border party structures. In doing so, it contributes to a better understanding of party organisation in increasingly complex territorial contexts.