The underlying assumption of constitutional pluralism, one of the dominant theories of EU legal scholarship, is a fundamental constitutional homogeneity amongst the EU Member States allowing for harmonious co‐existence and ‘constitutional tolerance’. This article challenges this assumption by demonstrating that the EU is characterised by a fundamental constitutional heterogeneity. It argues that the Member States are influenced by at least three different ‘varieties of constitutionalism’: ‘post‐fascist constitutionalism’, ‘evolutionary constitutionalism’ and ‘post‐communist constitutionalism’. The article shows that the type of constitutionalism dominant in a Member State influences its conception of the nature of the EU and its legal and political relationship to the project of European integration. The EU is therefore characterised by a fundamental constitutional asymmetry. The rise of authoritarianism in Poland and Hungary, while extreme, should thus not be treated as an exception to an otherwise constitutionally homogenous Union.

Signe Rehling Larsen is Fellow by Examination,Magdalen College,University of Oxford. This article is based on her  conference paper for the international conference held on 1–2 November 2018 at iCourts, the University of Copenhagen introducing the research project: ‘IMAGINE: European Constitutional Imaginaries: Utopias, Ideologies and the Other’. IMAGINE has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 803163).

The article can be downloaded at the Modern Law Review’s website.