Since the early 2000s, pro-European secessionist parties have pursued “independence in the EU” while becoming increasingly mainstream in European politics. This suggests that the process of European integration might sustain rather than hamper the quest for independence among non-sovereign regions in the EU. This development is puzzling since EU representatives have consistently argued in public that independence is an “internal matter” and that regions of EU member states would automatically lose EU membership upon secession. Previous research has so far overwhelmingly focused on pro-European secessionist parties at the national level, even though mobilization in the European Parliament (EP) has been a consistent component of their strategy. As a result, few studies have focused on how and to what extent the EP is used as a political arena in secessionist parties’ independence strategies.

This thesis examines how pro‑European secessionist parties advance their independence agendas in the EP and explores the role of European integration in contemporary secessionist politics. Although the EU has not delivered on secessionist parties’ wishes and expectations, these parties have continued to mobilize electoral support to secure representation in the EP, raising the question of how Europe matters in their pursuit of independence. The thesis addresses two research questions: how have pro-European secessionist parties used Europe in their independence strategies in the EP between 1999 and 2024, and what contextual factors help understand differences in how Europe is used in secessionist parties’ independence strategies? The thesis adopts a strategic constructivist perspective and develops a new conceptual framework based on the concept of “usage of Europe”, originally established by Sophie Jacquot and Cornelia Woll. The framework is used to structure a comparative study of three secessionist parties from Scotland and Catalonia: Scottish National Party (SNP); Esquerra Republicana de Catalunya (ERC) and Convergència i Unió/Partit Demòcrata Europeu Català/Junts per Catalunya (CiU/PDeCAT/Junts). 

The thesis combines qualitative content analysis of a novel dataset of EP text data with semi-structured interviews with Members of the European Parliament. The findings show that pro‑European secessionist parties have continuously used the EP to address independence, albeit the SNP has used Europe primarily pragmatically, whereas the Catalan parties have used it more idealistically, making Europe more central to their independence strategies. While the different usages of Europe are shaped by contextual factors, the study also shows that all parties engage in practices aiming at normalizing both themselves and their independence claims within the EP. Taken together, the findings suggests that despite the EU’s formal reluctance to facilitate secession,European integration still offers secessionist parties institutional and discursive resources and is therefore not perceived by them as a closed opportunity structure. The thesis thus makes both theoretical and empirical contributions to the study of secessionist politics in Europe.