Conor Kelly and Etain Tannam argue that Brexit reversed much of the progress of past decades in Northern Ireland by signifying a return by the UK government to a unilateral approach that prioritised traditional sovereignty in both its relations with the Irish government and with devolved governments. They conclude that Brexit has deeply destabilised the political settlement in Northern Ireland.

In the first 5 months of 2023, Northern Ireland was rarely far from our front pages as the Windsor Framework was negotiated between the UK government and European Commission in February, and the world’s media descended on Belfast for the Belfast/Good Friday Agreement’s 25th-anniversary celebrations in April. Yet, the Stormont institutions remain suspended, and the Democratic Unionist Party (DUP) has thus far refused to accept the Windsor Framework as the basis for returning to power-sharing.

To understand Brexit’s impact on the government’s policy, one must examine if joint UK-Irish EU membership between 1973 and 2016 impacted UK policy to Northern Ireland. We argue that while the Europeanisation of UK government policy towards Northern Ireland can be overstated, it had an indirect impact on the peace process by influencing the strategy of its key architect, former Social Democratic and Labour Party (SDLP) leader John Hume. In particular the EU’s model of  institutionalised cooperation and consensual policy-making has echoes in the 1998 Agreement. Thus, the process of de-Europeanisation since 2016 has had a severely negative effect on political stability within Northern Ireland and UK-Irish relations.