European integration and the future of nationalist parties [OSCAR BARBERA I ARESTÉ] This paper addresses some of the possible effects of European integration in the political parties that act in state and sub-state arenas. Furthermore, it tries to do so by revealing the possible impact in different areas of their organisation. To this end, the first part provides an in-depth analysis of the oft-forgotten role of parties in the building of Europe. The second part tackles possible scenarios towards which the European arena is moving in the next few years, and the different effects this may have on parties. The third and final part goes on to address the effects on nationalist parties.