UK Parliamentary Sovereignty in an Age of Constitutional Flux - Challenge, Centrality and Complacency

This paper is based on a lecture delivered to the Japanese Society for the Study of the British Constitution in Kyoto in September 2017. The purpose of this paper is to review recent developments in UK constitutional law to assess the broader implications for parliamentary sovereignty. The paper will explore constitutional developments relating to parliamentary sovereignty in three specific fields: (i) political; (ii) judicial; and (iii) legislative. This division is adopted in recognition of the multifaceted character of parliamentary sovereignty, which has implications in all of these different spheres of activity. First, the discussion of political developments will focus on the role of the notion of parliamentary sovereignty in the EU referendum campaign and its influence on the decisions taken in its aftermath. The second section will focus on judicial developments, both in the seminal case of Miller – widely understood to represent a vindication of parliamentary sovereignty – and in other recent cases which serve to complicate any such conclusion. In the third section, a range of legislative developments with implications for parliamentary sovereignty will be considered: including the permanence clauses and recognition of the Sewel convention now contained in devolution legislation, the legislation planned for the UK’s (transitional) exit from the EU, and the potential repurposing of the EU referendum locks created by Parliament in 2011.