To what extent has the politics of state restructuring been influenced by European integration? The paper addresses this question through an analysis of the conditions under which political parties exploit the European dimension in relation to state restructuring. Based on a Qualitative Comparative Analysis (QCA) of 127 party-election/referendum observations across 13 critical junctures of state restructuring in six European states, the paper shows that ‘Europe’ affects state restructuring primarily through the agency of regional-nationalist parties and only in critical junctures in which state restructuring conforms to a ‘bottom up’ as opposed to a ‘top down’ dynamic. These findings suggest that European integration has had a powerful but ‘punctuated’ influence on state restructuring and lend support to a ‘realist bargain’ theory of the connection between the two.