From staunch supporters to critical observers: Explaining the turn towards Euroscepticism among regionalist parties

Based on a new dataset, this article explains a turn towards Euroscepticism by regionalist parties from the early 2000s. Our findings point to the effects of cross-dimensional ideological linkages – positions adopted on the centre-periphery and left–right dimensions – and of an increasing formal regional involvement in European Union affairs without actual influence, which leaves regionalist (and especially secessionist) parties frustrated with the European Union multi-level system. Our findings substantiate the argument that regionalist parties are strongly supportive of economic integration but less supportive of political integration. They are also in line with the fall of the ‘Europe of the Regions’ thesis.