The paper presents a three-step approach to key constitutional issues in the European Union. The first step introduces the main descriptive elements of EU constitutionalism, highlighting some of the principal fields in which constitutional debate is presently clustering. Step two elaborates upon the tensions within EU constitutionalism by presenting a conceptual approach focusing upon the 'postnational' and procedural questions. Finally, in the third step, the paper sets out examples in order to demonstrate how the conceptual framework fits more closely with the emerging empirical reality of EU constitutional practices. It focuses upon events surrounding the inter-governmental conferences at which amendments to the EU treaties are agreed by the member states. The aim of the paper is to locate some of the tensions and relations which hold EU constitutionalism in place, rather than to capture its 'essence'.