LONDON — British Prime Minister Theresa May will travel to Brussels on Wednesday evening to meet European Commission President Jean-Claude Juncker as part of talks on future ties after Brexit, her office said on Tuesday.

May and Juncker would sit down at 5:30 p.m. (1630 GMT), the Commission said.

EU states are expected to finalize their work on a political declaration on the bloc’s future ties with Britain after Brexit. National envoys are due to meet the Commission’s negotiators on Tuesday evening to discuss a text.

The declaration is to accompany the UK’s withdrawal agreement which EU leaders hope to rubber-stamp at a summit this Sunday, which May will also attend.

Meanwhile the British PM is facing fresh pressure from her Northern Irish allies.

Eurosceptic members of May’s divided party seized the moment to launch a leadership challenge, but days later, have yet to muster the support needed for a no confidence vote.

Many MPs still oppose the Brexit deal, however, including the Democratic Unionist Party (DUP), which props up May’s government — and which late Monday used a budget vote to flex its muscles.

The Northern Irish party abstained on three votes, despite their deal to support the Conservatives on finance matters, and even sided with the opposition Labour party on a fourth.

“We had to do something to show our displeasure,” DUP Brexit spokesman Sammy Wilson told the BBC.

Without the support of the DUP’s 10 MPs, the Conservatives have no majority in the Commons, the 650-seat parliamentary chamber which will have the final vote on the Brexit deal.

This raises the risk that Britain ends its four-decade membership with the EU on March 29, 2019, with no other arrangement in place.

Labor Minister John Trickett said: “We no longer have a functioning government. With Brexit only a few months away, something has got to give.”

In an interview with the BBC on Tuesday, Justice Minister David Gauke sought to reassure the DUP, saying the Brexit deal was “the best option for us” and delivered on the 2016 EU referendum.

“I hope that the DUP and the others will look at the details of the deal and see this is the right way forward for the country, given the damage that would be done to us as a country were we not to have a deal, or were we to find that the referendum result couldn’t be delivered,” he said.

The deal agreed with the EU last week covers Britain’s financial settlement, expatriate citizens’ rights, and a 21-month post-Brexit transition period in which the two sides hope to agree a new trading relationship.

But the DUP and many Conservatives are outraged by the “backstop” plan that would keep Britain in the EU’s customs union, and Northern Ireland in elements of the single market, if this trade deal is not ready by then.

This is intended as an insurance plan to keep the border open between Northern Ireland and EU member Ireland if and until the new trade arrangements resolve the issue.

Wilson said the DUP’s defiance was “designed to send a message to the government: ‘Look, we have got an agreement with you but you have got to keep your side of the bargain otherwise we don’t feel obliged to keep ours’.

“She (May) has broken all of those promises — to the people of the United Kingdom, to her own party and to the people of Northern Ireland.”

She will then return on Sunday alongside the other 27 EU leaders to sign off the Brexit deal. — Agencies