Ben Lowry: Theresa May has ruthlessly but reluctantly felt she had to jettison unionism in Northern Ireland

She cast aside any notion that she would stand aside, despite the massive and mounting pressures on her.

A ruthless side was on display also.

It was the side to the prime minister that in 2016 summarily dismissed George Osborne, so ending the political career of the mooted successor to David Cameron.

Today, it was Northern Ireland unionists who were on the wrong side of Mrs May’s ruthlessness, even though she never mentioned unionists and even though none of the various journalists asked a question specifically about NI.

In explaining why she had chosen the course of action that she chose in this proposed withdrawal agreement with the EU, Mrs May explained that none of the various other options met the commitments that Britain had given last December over the backstop. The European Union would not accept anything else, she said.

This comment confirmed why Downing Street has abandoned its previous position that the EU assessment of the backstop was wrong.

It was the point at which Mrs May’s persistent rhetoric about avoiding a border in the Irish Sea gave way to the reality of such a border.

It was the moment at which the prime minister, without saying so explicitly, in effect acknowledged the decision she had taken in reaching this deal.

In fairness to Mrs May, she has not just chosen heedlessly to cast Northern Ireland aside. In fact, her unionism has been probably more emphatic than that of other prime ministers, all of whom tend to be unionist.

She has even persuaded the EU to allow the whole of the UK to stay in the customs union to avoid a customs (ie tariff) border in the Irish Sea.

However, realising that middle England will probably not tolerate the UK remaining in the customs union indefinitely, there is a mechanism for Great Britain to escape it. Northern Ireland (in effect) cannot leave.

At the same time, the government has agreed that Northern Ireland will stay in the single market, which means a regulatory border in the Irish Sea.

This means an immediate internal UK border in terms of (regulations) and probably also a future customs border between NI and GB in the future – ie, a full trade Irish Sea border.

It means that the Province will forever be on the EU side of the customs/regulations divide, which will lead to political demands for NI to have MEPs and in the meantime to have Dublin as its proxy representative on such matters.

It means that if Brexit succeeds and the UK increasingly diverges more from the EU over time, we will always be on the EU side. It is, from a unionist perspective, a disastrous outcome.

The prime minister’s unionism is not fake, it is patently real, so she knows how unsatisfactory this outcome is. But she had a choice between making such a concession and no deal, and it has been apparent for months that she is – as one wit put it on Twitter – clearly of the view that a bad deal is better than no deal (the opposite of her oft-repeated pledge).

Faced with that unpalatable choice of no deal or standing fully by NI, Mrs May has jettisoned her pledge to us.

This deal will probably be rejected by MPs, but now London has shown its hand and the EU will never accept less. Any deal like this will be the worst imposition on unionists since 1985’s Anglo Irish Agreement, from which we have not fully recovered.

• Ben Lowry (@BenLowry2) is News Letter deputy editor