Territorial Differentiation in EU Law: Can Scotland and Northern Ireland Remain in the EU and/or the Single Market?

Abstract In the Brexit referendum of 23 June 2016, voters in England and Wales voted to leave the EU, while in Scotland and Northern Ireland they voted to remain. Following that, there has been a debate about how it would be possible to achieve the continuing presence in the single market of the UK constituent nations that do not want to be taken out against their will. This paper explores two pathways for Scotland and Northern Ireland to remain in the EU and/or the single market. The first entails the achievement of Scottish independence and the reunification of Ireland through democratic referendums. To this effect, the paper reviews the right of secession of those two constituent nations under UK constitutional law. It revisits the debate on the appropriate legal basis regulating Scotland’s future EU accession and discusses the Irish reunification from an EU law perspective. The second pathway explores how it would be possible for Scotland and Northern Ireland to remain in the EU and/or the single market even without seceding from the UK. In order to do that, the paper points to the remarkable flexibility of the EU legal order as evidenced in numerous cases of differentiated application of Union law. The paper shows that the EU possesses the necessary legal instruments to accommodate the divergent aspirations of the UK constituent nations.