On both sides of the Irish border, the United Kingdom referendum result in favour of leaving the European Union has become the constant backdrop to all sorts of policy discussions, including the very possibility of continuing with the Northern Ireland power-sharing agreement. If a new Northern Ireland Executive can be formed from the leadership of the Democratic Unionist Party (DUP) and Sinn Féin, representing the unionist (and loyalist) and nationalist (and republican) communities, Brexit will be high on its agenda. But finding a common stance will be difficult. In Brexit shorthand, the DUP are Leavers, Sinn Féin Remainers. And the crucial issue will be the border.

Sinn Féin were the clear winners in the recent Northern Ireland election, which arose from an impasse within the old Executive. Sinn Féin wanted the First Minister, DUP leader Arlene Foster, to stand down, at least while her role in a public-spending fiasco concerning green energy was sorted out. But almost by definition, something Sinn Féin wanted was therefore something the DUP did not.