May’s Brexit promise cannot be a watertight guarantee

Britain wants a UK-wide customs arrangement to be written into the legally-binding withdrawal agreement

Theresa May's letter to Arlene Foster and Nigel Dodds is peppered with reassuring assertions of the prime minister's commitment to the Union and to avoiding a border in the Irish Sea after Brexit.

But the DUP leader and deputy leader read the letter correctly as an acknowledgment that a UK-wide customs backstop will not eliminate or replace Northern Ireland-specific measures to guarantee that there will be no hard border on the island of Ireland.

May was responding to a letter from Foster and Dodds warning against any Northern Ireland-specific arrangements.

“Our position has always been and remains that we will not support arrangements that leave Northern Ireland separated from the rest of the United Kingdom and tied to the European Union’s customs or regulatory regimes,” they wrote.


May said that neither Britain nor the EU wanted the backstop to be used, adding that it would have to be temporary, although it would not be time-limited. This is consistent with the demand from Dublin and Brussels that the backstop would remain in place “unless and until” a permanent solution was found to ensure that the Border stayed open.

Ultimate insurance policy

Britain wants a UK-wide customs arrangement to be written into the legally-binding withdrawal agreement so that it would come into effect instead of a Northern Ireland-specific backstop if a free trade deal is not in place when the post-Brexit transition period ends. The EU insists that Northern Ireland-specific backstop arrangements must also be written into the withdrawal agreement as an ultimate insurance policy.

“I am clear that I could not accept there being any circumstances or conditions in which that ‘backstop to the backstop’, which would break up the UK customs territory, could come in to force,” the prime minister said.

What the DUP has correctly concluded is that, if the Northern Ireland-specific backstop is in the agreement, there is at least a possibility that it will come into force in the future. In their letter to the prime minister, Foster and Dodds also expressed concerns about the prospect of Northern Ireland remaining aligned with EU regulations that the rest of the UK would not have to follow.

“We are resolutely opposed to any Northern Ireland specific backstop which not only leaves Northern Ireland aligned to specific sectoral EU market regulations but is, when operational, not time-limited by date. In such circumstances, Northern Ireland would inevitably be subject to greater EU regulation over time while Great Britain would not. By definition that would bring about new regulatory barriers within the United Kingdom and damage Northern Ireland’s place within the UK internal market,” they wrote.

‘Regulatory checks’

In her response, May pointed out that the island of Ireland formed a single electricity market and animal health territory, and that 30 types of regulatory checks were already in place between Great Britain and Northern Ireland. She said some “specific alignment solutions” for Northern Ireland would be necessary but suggested that Britain would voluntarily follow any EU regulations that apply in Northern Ireland for as long as the backstop is in place.

“We are also reflecting on how to give expression to the pragmatic and political reality that, given that any backstop would apply only in time limited circumstances and for a temporary period with a view to that future UK-wide arrangement, we would not expect regulations to diverge between Great Britain and Northern Ireland during a backstop scenario,” she said.

This promise is not a watertight guarantee, however, as a future British government could decide to stop copying Northern Ireland’s regulations, instead allowing the North to remain in the EU’s regulatory orbit while the rest of the UK diverges.