Theresa May dealt a blow to Ireland in her Brexit white paper when she said she wanted in effect to leave the EU customs union, confirming Brexit poses a huge threat to frictionless cross-border trade on the island of Ireland, the mainstay of the Irish economy.

The Irish Ambassador to the UK, Daniel Mulhall said last month that comprehensive customs and border checks between Ireland and Northern Ireland are not remotely possible

Northern Ireland polled more europhilic than other regions in the UK before the election. Its Remain vote of 55.7 per cent was the third strongest in the country. Nationalists wanted the UK to remain in the EU, but unionists generally wanted to leave. Sinn Féin, the SDLP, the Ulster Unionists, Alliance and the Green Party wanted to stay. The Irish government also wanted a remain vote. The DUP, the TUV and the left-wing People before Profit party backed Brexit.

As Sinn Fein and the DUP jostle for position in a new power sharing agreement at Stormont the Brexit divide has come to the fore. If the parties are unable to agree an accommodation, we may yet see a return to direct rule of the province from Westminster.

Remain campaigners warned that a Brexit would lead to the re-establishing of a harder border along the 310-mile frontier between Northern Ireland and the Republic in order to collect customs tariffs and stop EU nationals who would no longer enjoy the right to move freely to the UK from using the North as a backdoor immigration route.  Campaigners also warned, in the run up to the referendum, that the introduction of a harder border would once again put North-South relations under strain, endangering both the Peace Process and the economic dividends of peace.

They also warned that a Brexit vote is likely, sooner or later, to trigger another Scottish independence referendum which – if Scotland voted to leave the Union – would destabilise the UK constitutional settlement, with potential knock-on effects for Northern Ireland.

Brexit is expected to have a disproportionate impact on Northern Ireland’s economy which is reliant on exports to the EU, including in the food and agriculture sectors which would be hit hardest if the UK ends up paying EU tariffs.

The House of Lords EU select committee have published a comprehensive report on the matter titled Brexit: UK-Irish Relations. Baroness Suttie (Libdem Shadow Secretary of State for Northern Ireland) was one of three Lib Dem Lords on the committee and will be discussing key aspects of the report at York on Saint Patrick’s Day. The fringe meeting will be held from 20:15 to 21:30 on March 17 in meeting room 5 of the Novotel hotel.  Immediately following the debate we will be joining the York Irish Association St Patrick’s day festival in a marquee at nearby St Sampson’s Square.

* Joe Bourke is an accountant and university lecturer, Chair of ALTER, and Chair of Hounslow Liberal Democrats.