Partisan Anatomy of the European Parliament (1). Methodological Note for the Study of National Parties in a Transnational Setting

This article presents a research program on the partisan composition of the European Parliament (EP) at the level of national parties. It aims to trace changes in the EP’s political structuration, conceived as an indicator of the reconfiguration of transnational political cleavages. To do so, the article proposes to produce a long-term ‘partisan anatomy’ of the EP by identifying MEPs’ affiliations to national parties and to European parliamentary groups. This undertaking raises several practical problems due to the phenomenon of ‘partisan ambiguity’, which this methodological note seeks to analyze and resolve, using the first year of the 10th Parliament as its working base.