Constitutional Reform by Legal Transplantation: The United Kingdom Internal Market Act 2020

This article develops the comparative law framework on legal transplantation to theorise the impact of the United Kingdom Internal Market Act 2020 (UKIMA) on the UK constitution across three registers of analysis—the territorial, the material and the conceptual. It arrives at three conclusions. First, in relation to the territorial constitution, this article argues that the UKIMA introduces something transformative: the concept of an internal market as a shared regulatory space that cuts across the respective competences of the UK and devolved legislatures. Secondly, the legal transplant framework points to the introduction of a powerful commitment to the principles of a liberal market economy as the basis of the UK’s material constitution. Finally, regarding the conceptual constitution, this article concludes that the UKIMA effects a qualitative change to established patterns of judicial review through its co-opting of courts as agents to secure the foundations of the newly recast material constitution.