Brexit and the Trouble with an Uncodified Constitution: R (Miller) v Secretary of State for Exiting the European Union

Abstract

On June 23, 2016, the United Kingdom voted, unexpectedly, to leave the European Union. That such a decision would have constitutional implications was not surprising, but the vote also caused an unforeseen constitutional crisis: who has the power to begin the process of leaving the European Union? While the government believed that it could exercise its Crown prerogative to conduct foreign affairs, others demanded that Parliament must authorize the decision to leave. The United Kingdom’s constitution, relying mostly on precedent and custom, seemed to provide no answer. The decision was left to the courts and there ensued many months of constitutional and political uncertainty as the so-called “Brexit litigation” worked its way through the legal system. The Brexit litigation has been described as “the most important constitutional case for a generation.” It caused much excitement and engendered much debate amongst both lawyers and the general public in Britain throughout the fall of 2016 and into early 2017.7 This Article seeks to explain the constitutional arrangements that led to the need for the litigation. It will provide a detailed explanation of the case and the decision of the court, argue that the uncertainty caused was both unnecessary and avoidable, and make some suggestions about changes that could be made to the United Kingdom’s constitution to prevent such a situation from occurring in the future.