Constitutional law and secession in Spain

This chapter discusses the Spanish constitutional framework and the debates surrounding its application to attempts by a sub-state unit or nation to secede from the Spanish state. Due to the constitutional silence on this question, the chapter focuses on the three most relevant sets of constitutional provisions for these debates: first, those which provide the foundations for Spain’s plurinational state; second, those which regulate the holding of referendums; and third, those which apply to the reform of the Constitution itself. Drawing from the examples of the Basque ‘Ibarretxe Plan’ and the more recent Catalan independence process, on the one hand, and on the response of the Spanish authorities on the other, the chapter concludes that the question of whether, and if so, how, secession is possible under the Spanish Constitution in response to sustained and democratically expressed support for such an option in a sub-state nation or unit has not yet been successfully resolved.