Brexit: Theresa May's withdrawal deal in disarray as DUP vows to vote against it after she offers to resign

MPs also held a series of votes to determine if any compromise can be found to break the Brexit deadlock – but nothing gained a majority

Theresa May’s plan to secure Tory MPs’ backing for her Brexit deal by promising to resign has been blown apart after her DUP partners in government vowed to block it in a new vote.

Ms May announced she will resign within weeks if Tory rebels desperate to see the back of her, allow the Brexit deal she struck with Brussels to pass through the House of Commons.

The move did see Boris Johnson and other rebels finally fall into line, but within hours the boost was wiped out when DUP leader Arlene Foster branded the prime minister’s Brexit plan an “unacceptable threat” to the UK’s integrity.

With the success of Ms May’s final gambit now heavily in doubt, MPs held a series of votes to determine if any compromise can be found to break the parliamentary deadlock – but none of the eight options tested gained a majority.

Earlier in the day cabinet ministers went on the airwaves to show support after Ms May’s pledge and to urge MPs to get behind her Brexit deal, but several will now ramp up preparations for a leadership contest with the PM looking fatally weakened.

Several Conservatives told The Independent that with her Brexit plan on its last legs and parliament having so far failed to find an alternative, a new election now appears a very real possibility.

The prime minister revealed her pledge to resign at a closed meeting of the backbench Conservative 1922 Committee, telling those present: “I have heard very clearly the mood of the parliamentary party. I know there is a desire for a new approach – and new leadership – in the second phase of the Brexit negotiations – and I won’t stand in the way of that.

“I know some people are worried that if you vote for the withdrawal agreement, I will take that as a mandate to rush on into phase two without the debate we need to have. I won’t – I hear what you are saying.”

Ministers had set the scene for an all-or-nothing third vote on her deal to potentially take place on Friday 29 March – the day Britain was originally supposed to leave the EU.

While the prime minister did not give an exact date for her departure, the thinking inside Downing Street earlier in the day was that if the deal were to pass, a leadership contest would begin on 22 May, the day of Brexit under more recent plans.

I have heard very clearly the mood of the parliamentary party. I know there is a desire for a new approach – and new leadership – in the second phase of the Brexit negotiations – and I won’t stand in the way of that

Prime Minister Theresa May

It would mean the critical next phase of negotiations would have been taken up by a new Tory leader, one who will have been elected by the vehemently Eurosceptic party membership.

Other Tory rebels who following Ms May’s announcement said they would now back the PM’s deal included Iain Duncan Smith, John Whittingdale, Conor Burns, Pauline Latham, Shailesh Vara, Robert Courts, Charlie Elphicke and Sheryll Murray.

Others were less convinced, such as Steve Baker, deputy chair of the Brexit-backing European Research Group, who raged during the meeting that those backing the deal are “fools and knaves and cowards”.

Mr Baker said: “I could tear this place down and bulldoze it into the river.”

Nonetheless, for a few hours there was hope that Ms May might just get the support she needed until the DUP put out its statement of opposition.

Ms Foster said: “What we can’t agree to is something that threatens the union, that has a strategic risk to the union.

“For us in the Democratic Unionist Party, the union will always come first and that has been the issue right from the beginning of all of this.”

The government is also still yet to set out how it will get round Commons speaker John Bercow, who has said he will not allow another vote on Ms May’s deal unless it is a significantly different proposition.

Home secretary Sajid Javid, justice secretary David Gauke and communities secretary James Brokenshire were among those who put out comments of support for the PM.

But Mr Javid, Mr Johnson, environment secretary Michael Gove, ex-Brexit secretary Dominic Raab, foreign secretary Jeremy Hunt and Commons leader Andrea Leadsom are among those likely to be in the running now that Ms May has publicly contemplated the end of her tenure.

One cabinet source gave a blunt appraisal of the PM’s speech, telling The Independent it was “quite sad, but necessary”.

In an apt demonstration of just how deadlocked parliament is, MPs also failed to find a Commons majority for any Brexit plan despite voting on eight different options.

The eight options put to a vote included a second referendum, a no-deal scenario, a customs union, revoking Article 50 and membership of the European Economic Area.

The options that were closest to securing a majority were a customs union and a new referendum, and MPs will try again on Monday to negotiate something that might enjoy a majority.

But Brexit secretary Stephen Barclay said the results underline why Ms May’s deal is still the “best option”, as it is already a compromise.

The impasse served to heighten the expectation of a new election, with one senior Tory telling The Independent: “It’s grim and no one wants one, but what do you do?

“Anything that comes out of the MPs’ process is going to be a grubby compromise. But we’ve already got one of those and it’s been rejected.”