The paper shows that regionalist parties have been on average supporters of European integration but also that their level of support has considerably decreased in the 2000s. In order to explain why, we investigate the determinants of regionalist parties’ positioning on European integration across time and space. The study is based on an original dataset which includes 34 regionalist parties across six European countries and along four decades (1970s-2000s). Our analysis shows that the positions on European integration adopted by regionalist parties are strongly linked to their level of left-right and centre-periphery radicalism: left-right radicals tend to be more Eurosceptic than left-right centrist/mainstream parties; secessionists tend to be more Eurosceptic than autonomist parties. Left-right radicals and secessionist parties are invariably Eurosceptic, while left-right centrists/mainstream and autonomist parties are almost invariably Europhile. Our findings also show that migration of state powers upwards to the EU level or downwards to the regions has impacts on regionalist parties’ stances of European integration. These impacts are conditional upon the positions adopted along the left-right and centre-periphery dimensions. However, increases in European authority tend to produce less supportive positions, while the effect of regional authority is more complex and dependent on the dimensions of authority: self-rule or shared-rule. Given the increase of secessionist positions amongst regionalist parties in the 2000s, our findings appear to support the thesis that sees a decrease in support for European integration as a consequence of the demise of the ‘Europe of regions’ vision.
