“Roundheads vs Cavaliers” : The British Constitution and Parliamentary sovereignty in the face of Brexit

Abstract

Brexit has been one of the defining features of Theresa May’s premiership. In the summer of 2016, when the EU referendum’s results forced David Cameron out of Downing Street, Theresa May took over as PM with the task of seeing the United Kingdom through the withdrawal process. The first few months of her term in office have proven all the more difficult as the unprecedented nature of Brexit has led to high-profile legal challenges in the courts, especially in R (on the application of Miller) v Secretary of State for leaving the European Union. In the latter, the Supreme Court established that notification of withdrawal from the EU could only be triggered by a vote in Parliament, hereby strengthening Parliament’s role in the Brexit procedure as opposed to the government’s Crown prerogatives. This fight between supporters of the principle of Parliamentary sovereignty, as opposed to the government’s, has encouraged several observers to describe Britain’s current political situation in Civil War-era terms, as “Roundheads versus Cavaliers”. Nevertheless, Brexit’s intricacies have long outgrown this procedural question and have put several aspects of the British Constitution to the test, from the separation of powers to the representative function of MPs. All in all, the use of this Civil War-era metaphor aptly describes the many divisions carved out by Brexit within the UK government, but also within the Conservative party itself.