This article aims to make an analysis of presentation of Patricia Popelier, professor at the University of Antwerp, her presentation “Sub-states and the European Union: constitutional strategies”. Namely to analyse the impact of regional realities as sub-states on the multi-tiered system that the European Union has become, when it comes to establishing their own position within the European Union.

European Union. Regions. Participation. Joint Perspective. Federal Perspective. Confederal Perpective. The Basque Country.