#Brexit negotiations collapsed into chaos on Monday after a clumsy attempt to fudge the issue of Northern Ireland’s border with the EU. Under pressure from Irish premier Leo Varadkar and the European Commission, British leader Theresa May agreed that many of #Northern Ireland’s laws would stay in “continued regulatory alignment” with the EU after Britain leaves in 2019.

Unfortunately for May, she didn’t bother to run this idea past the Democratic #Unionist Party, the largest in Northern Ireland. In one way this is understandable – the DUP is a unionist party, after all, and was never likely to support anything that weakened the union between Northern Ireland and the rest of the UK.

The problem is that May’s minority government depends on the support of the DUP’s ten MPs to pass laws, under an agreement reached after May lost her parliamentary majority in this June’s disastrous general election. If the DUP withdraw their support, it’s unlikely she could survive as prime minister for more than a few days – so May’s attempted compromise was a high-risk gamble. And she lost.

A doomed gamble?

What’s most surprising is that there was never any real chance of her pulling it off. May apparently gave DUP leader Arlene Foster a verbal briefing about the proposed deal but didn’t show her the text. European politicians did get to see the text – and, as Theresa May sat down to a working lunch with EU president Jean-Claude Juncker, her proposals were leaked to the Irish media. Within minutes alarmed DUP politicians were briefing the press that “this is not our understanding of the UK government’s position,” while Foster picked up the phone and placed an emergency call to May.

In a farcical scene May, who had been ready to sign the agreement with Juncker, was dragged out of her lunch meeting to talk to the outraged Foster. EU sources say she spent at least fifteen minutes trying to persuade Foster to accept the “compromise” wording – but in the end, she had to go back into the lunch meeting and tell Juncker the offer was no longer on the table.

Where now for May?

May has now painted herself into a corner. She won’t be able to make another attempt at what the DUP called “creative ambiguity,” because the unionists and many of her party members will be watching what she does very closely.

The EU has now given May four days to find a solution to the Irish border; if she fails, it’s unlikely that talks between Britain and the EU will move on from discussing how the UK leaves to developing a trade deal for the future. May has already offered to hand the EU up to $70 billion in exchange for trade talks, as well as to give European courts the ability to keep making laws for Britain. Many Conservative MPs feel she’s already given too much away, and if she tries to make more concessions, it’s likely she’ll come under pressure to walk away from talks. That would mean Britain is leaving without a deal and becoming a free-trading nation – something May has always been opposed to.