INTRODUCTION

The United Kingdom (UK) Government's decision to trigger Article 50 TEU to manage the UK's exit from the European Union (EU) has thrust its courts into the media spotlight. In particular, the English and Northern Irish High Courts and, subsequently, UK Supreme Court (UKSC), have been drawn into a series of legal disputes over the scope of the executive's prerogative powers and the competences of the devolved administrations.

This chapter looks ahead to changes to the institutional functions of UK courts within the domestic legal order as a consequence of the UK's departure from the EU. More precisely, it forecasts potentially far-reaching changes to the nature of UK courts ‘institutional functions post-Brexit as a result of the anticipated repeal of the European Communities Act 1972 (ECA). For the duration of the UK's membership of the (now) EU, that Act has functioned as the source of the domestic ‘constitutional instruction’ to UK courts to give internal effect to EU law in proceedings falling within the scope of Union law. In summary, the ECA instructs UK courts, on their own reading thereof, to attribute direct effect and primacy to EU norms and, further, to interpret provisions of Union law in conformity with principles established by the Court of Justice.

The UK's exit from the European Union is tied domestically to an express political commitment to repeal the ECA through the enactment of the Great Repeal Bill (GRB). The GRB (forthcoming, 2017) will be used, first, to ‘nationalise’ the body of law that currently falls within the scope of the EU Treaties – the EU acquis. It will also, secondly, establish new delegated powers to enable the repeal or subsequent amendment of specific aspects of the nationalised EU acquis post withdrawal. Both aspects are already attracting considerable parliamentary and academic scrutiny – with the spotlight on proposals to use the GRB to establish sweeping new executive competences to amend primary legislation.