DESPERATE Theresa May will beg European leaders to save her career after pulling the Commons vote on her Brexit plan - but they have already said no.

In a humiliating climbdown, the PM was forced to admit that her deal - due to be voted on tomorrow - would be "rejected by a significant margin" by furious MPs.

13 Theresa May speaking in the House of Commons Credit: PRU

Facing a huge defeat with dozens of MPs rebelling, Mrs May announced she would pull the planned vote.

She will now travel to Europe over the coming days in the hope of securing new reassurances from fellow EU leaders to allay MPs' concerns about proposed backstop arrangements for the Irish border.

However European Council president Donald Tusk said there was no hope of renegotiation.

He said: "We will not renegotiate the deal, including the backstop, but we are ready to discuss how to facilitate UK ratification. As time is running out, we will also discuss our preparedness for a no-deal scenario."

And a spokeswoman for European Commission president Jean-Claude Juncker poured cold water on any prospect of a renegotiation of the Withdrawal Agreement.

Speaking ahead of Mrs May's statement, the spokeswoman said: "This deal is the best and only deal possible. We will not renegotiate."

Irish Prime Minister Leo Varadkar ruled out reopening talks around the backstop, saying it was not possible to reopen any aspect of the Withdrawal Agreement without reopening all of it.

Downing Street was unable to give any indication of when the vote will now be held, saying that this would depend on how quickly Mrs May is able to secure the assurances which will satisfy MPs.

Speaking today, the PM said: "I've listened very carefully to what has been said in this chamber and out of it by members on all sides.

"From listening to those views it is clear that while there is broad support for many of the key aspects of the deal, on one issue – the Northern Ireland backstop – there remains widespread and deep concern.

13 European Council president Donald Tusk said 'we will not renegotiate the deal' Credit: Reuters

13 The PM vowed to push on with her Brexit deal Credit: PA:Press Association

"As a result, if we went ahead and held the vote tomorrow the deal would be rejected by a significant margin. We will therefore defer the vote scheduled for tomorrow."

She will now travel around the continent to try and get a better deal on the "Irish backstop" ahead of a Brussels summit on Thursday.

The PM told the Commons: "I spoke to a number of EU leaders over the weekend, and in advance of the European Council I will go to see my counterparts in other member states and the leadership of the Council and the Commission.

"I will discuss with them the clear concerns that this house has expressed. We are also looking closely at new ways of empowering the House of Commons to ensure that any provision for a backstop has democratic legitimacy."

Theresa May told she's had a 'premature parliamentary ejaculation' over Brexit by Labour MP Rupa Huq

13 Chief Whip Julian Smith is responsible for pushing the deal through Parliament Credit: AP:Associated Press

13 Environment Secretary Michael Gove has backed the Brexit deal Credit: London News Pictures

The backstop - designed to keep the Irish border open - would trap the UK in the customs union, and require checks between Great Britain and Northern Ireland.

Dozens of Tory MPs have said they can't back Mrs May's deal unless there is a mechanism for Britain to get out of the backstop without the EU's permission.

But the PM warned that if the Commons blocks her withdrawal agreement, Brexit could be cancelled altogether - or we could crash out of the EU without any deal at all.

She asked: "Does this house want to deliver Brexit? And if it does, does it want to do so through reaching an agreement with the EU?

"If the answer is yes, and I believe that is the answer of the majority of this House, then we all have to ask ourselves whether we are prepared to make a compromise. Because there will be no enduring and successful Brexit without some compromise on both sides of the debate."

13 Mrs May postponed a parliamentary vote on her Brexit deal today Credit: AFP

13 European bosses have said they won't renegotiate the deal Credit: Reuters

13 Campaigners handed out "Brexit fudge" in Westminster today Credit: Rex Features

Theresa May: 'Does this House want to deliver Brexit and with an EU agreement?'

Mrs May concluded: "Even though I voted Remain, from the moment I took up the responsibility of being Prime Minister of this great country I have known that my duty is to honour the result of that vote.

"And I have been just as determined to protect the jobs that put food on the tables of working families and the security partnerships that keep each one of us safe.

"And that is what this deal does. It gives us control of our borders, our money and our laws. It protects jobs, security and our Union. It is the right deal for Britain.

"I am determined to do all I can to secure the reassurances this house requires, to get this deal over the line and deliver for the British people."

But quizzed on when she would hold the rearranged vote, the PM refused to confirm when it would be - saying only that it will be before a deadline of January 21.

Brexiteers were already quick to tell Mrs May today that it wouldn't be enough to simply tinker around the edges of her deal.

Jacob Rees-Mogg told journalists this evening that changing the backstop wouldn't be enough to get him to vote for it.

He said the result was inevitable and it would get rejected "unless there is a new Prime Minister".

"This is a rotten day for the government. And it is a humiliating day... I think the feeling is sad that the government is in such a mess."

13 Donald Tusk said the deal can't be re-opened

As Mrs May fights for her deal - and her career:

Speaker John Bercow suggested it would be undemocratic to pull the vote without the permission of MPs

Jeremy Corbyn urged her to quit as Labour considered holding a vote of no confidence

Brexiteer Jacob Rees-Mogg said the PM should "govern or quit"

Mrs May's DUP ally Nigel Dodds said she wasn't listening to colleagues

European leaders warned it would be tricky to make major changes to the existing deal

Tomorrow's Cabinet meeting was suddenly cancelled

Meanwhile, Euro judges ruled that Britain can cancel Brexit without permission from Europe

Former PM David Cameron has said he does not regret calling the referendum which led to Brexit

More than 100 Tory MPs have spoken out against the withdrawal agreement as it currently stands.

13 Boris Johnson is plotting a challenge to Mrs May Credit: London News Pictures

Chancellor Philip Hammond ignores question asking if he still backs the Brexit deal 'as PM Theresa May postpones Commons vote'

That put Mrs May on course for the worst Conservative rebellion in history - sparking a possible leadership crisis or even a fresh election bringing Jeremy Corbyn to power.

Critics hit out at the PM's decision to pull the vote - Nicola Sturgeon blasted: "Pathetic cowardice it is from PM. Yet again the interests of the Tory party are a higher priority for her than anything else."

Jeremy Corbyn added: "The Government has decided Theresa May's Brexit deal is so disastrous that it has taken the desperate step of delaying its own vote at the eleventh hour."

Nigel Dodds of the DUP, which is propping up Mrs May in power, said in the Commons: "“Doesn’t she get it by now that the withdrawal agreement isn’t acceptable to this house?

"Please, Prime Minister, really do start listening and come back with changes to the Withdrawal Agreement or it really will be voted down."

His colleague Sammy Wilson raged: "Every time she comes back here with her tail between her legs, she humiliates the British people - when will she stand up to the EU?"

What happens next after PM scraps vote on Brexit deal? THERESA May's Brexit strategy is in tatters after she was forced to pull tomorrow's Commons vote. The future is now uncertain - with a new deal, No Deal Brexit or even a second referendum possibly on the table. Mrs May this afternoon confirmed that the vote is delayed, with Commons Leader Andrea Leadsom set to announce the parliamentary procedure used to pull the motion from the agenda. The PM is then scheduled to travel around Europe pressuring EU leaders to give her a better deal ahead of a summit in Brussels starting on Thursday. Dozens of MPs have said they can never vote for the withdrawal agreement unless it offers a guarantee that Britain can't be trapped in the backstop. If she succeeds in tweaking the deal, it could return to the Commons either next week or after Christmas, with January 21 the deadline. But the Government could still lose the rearranged vote - which would trigger a letter from Mrs May setting out the way forward. MPs would be free to amend the PM's statement, directing ministers to adopt a different strategy such as calling a second referendum. Or the Government could adopt a radically different strategy such as pivoting to a "Norway-style" Brexit which keeps Britain in the single market. But without MPs agreeing on a new path, Britain will be on course to crash out of the EU without any deal. Mrs May's own position could also be under threat - Labour have threatened to call a vote of confidence in Parliament which would topple the Government. And the PM will face a challenge to her leadership of the Tory party if 48 of her colleagues write letters calling for her to go.

13 The PM summoned Cabinet ministers for a conference call this morning Credit: Getty Images - Getty

And pro-EU Tory MP Anna Soubry told The Sun: "I fear we are becoming the laughing stock of the world."

But when she was accused of "bottling it" by pulling her vote, the PM hit back saying: "If I was bottling it, I wouldn't have come to this chamber and been on my feet already for two and a half hours."

This morning a No10 spokesman claimed Mrs May still intended to let MPs vote on her deal tomorrow.

But minutes later she spoke to the Cabinet in an emergency conference call - then announced she would be making a Commons statement.

It came after a string of weekend phone calls with European heads of state.

Mrs May called Angela Merkel, Ireland's Leo Varadkar, top Eurocrats Donald Tusk and Jean-Claude Juncker, and Dutch PM Mark Rutte.

The Sun was the first to report a week ago that the Government was considering pulling tomorrow's vote instead of suffering a public humiliation.

13 Brexit Secretary Stephen Barclay in Downing Street Credit: AFP

13 The PM is under pressure from all sides

Ministers this morning insisted the PM did still have a chance of winning the vote - hours before it was pulled.

Foreign Office Minister Alan Duncan hit out at the "wreckers" and called for the Tories to unite behind Mrs May.

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But Boris Johnson said the deal could be fixed as long as the PM ditched the backstop.

He wrote in the Daily Telegraph: "We are told that the EU does not even like the backstop.

"Well, if the EU doesn't like it, and the UK Government doesn't like it, and the British people don't like it, why on earth is it there? Let us get rid of it and move on."

Hunt warns of 'real risks' if MPs reject Brexit deal

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