Parliamentary sovereignty and the protocol pincer

Abstract It is May 2030 and Stormont heads into its fourth Assembly election in eight years. Voters walk past election posters loudly praising and denouncing the Northern Ireland Protocol. As with the other Assembly elections since Brexit, the Protocol occupies centre-stage. Voters are under no delusion: the new Assembly will be as polarised as ever, no matter its party-political make-up. The legal backdrop to this (not entirely unfeasible) future is complex: the UK's Withdrawal Agreement has meant the emergence of a regulatory border between Great Britain and Northern Ireland. The consequences which flow from this have been swift and myriad: trade barriers and social unrest, barely a year after withdrawal. The focus of this paper, however, is the impact of these changes on the UK constitution. I will examine two landmark judgments of the UK Supreme Court, applying the themes arising in these cases to the legislation which incorporated the Protocol into UK domestic law. In so doing, I will argue that, far from ‘taking back control’, the UK Parliament has instead erected significant new barriers to its ability to ‘make or unmake any law whatever’ for the whole of the UK.