Theresa May has been accused of a “shameful surrender” after urging Tory Brexiteers to accept the political reality that MPs would not allow Britain to leave the EU without a deal.

The Commons clash came after the Prime Minister opened a crisis Cabinet meeting by telling senior colleagues a no-deal Brexit was no longer a viable option because of MPs' opposition to it.

One minister further suggested that Mrs May had also raised the threat of a no-deal to the Union.

He noted this was “the first time she has said it so definitively,” adding: “It is the issue of the Union[that] seems to be what has really convinced her.”

Nationalists in Northern Ireland have been pushing for a border poll should there be a no-deal Brexit while Nationalists in Scotland have been pushing for a second independence referendum.

David Mundell, the Scottish Secretary, has repeatedly warned that a no-deal Brexit would be the “biggest threat to the Union”.

In her Commons statement, the PM stressed how she had wanted to deliver Brexit on March 29 but told MPs: “I am conscious of my duties as Prime Minister to all parts of our United Kingdom and of the damage to that Union leaving without a deal could do when one part of it is without devolved government and unable therefore to prepare properly.”

During the latest debate on Brexit, Crispin Blunt, a senior Conservative backbencher, took his party leader to task, accusing her of acting under orders from a "Remainer Parliament" and claiming she had "put the final torpedo" in her own Brexit deal.

The former Justice Minister claimed that Mrs May's comments represented "the most shameful surrender by a British leader since Singapore in 1942,” when the island city-state surrendered to Japan, something Sir Winston Churchill described as a "heavy and far-reaching military defeat".

But the PM, noting how the Commons had voted twice to reject a no-deal outcome, told colleagues: "We must confront the reality of the hard choices before us. Unless this House agrees to it, no-deal will not happen."

She stressed the Commons “may very well continue to vote to reject a no-deal," pointing out how the SNP had already indicated it would move a vote "to reverse the whole result of the referendum”.

She added: “The reality is this House has shown its intention to do everything it can to take no-deal off the table and...if we are going to deliver Brexit, then we need to recognise that.”

Earlier, Jeremy Corbyn said the Government's Brexit approach had become a “national embarrassment" and Mrs May’s deal was “dead”.

The Labour leader told MPs: "Rather than trying to engineer a way to bring back the same twice-rejected deal, will the Prime Minister instead allow, rather than fight, plans for indicative votes?”

He added: "She cannot both accept her deal does not have the numbers and stand in the way of finding an alternative that may have the numbers."

Mrs May refused to commit to respecting the result of any indicative votes, saying, to opposition jeers: “It's important nobody would want to support an option which contradicted the manifesto on which they stood for election to this House.

"MPs elected to this House at this time have a duty to respect the result of the referendum that took place in 2016 and attempts to stop that result being put into place or attempts to change the result of that referendum are not respecting the voters and not respecting our democracy."

But the SNP’s Ian Blackford asked: "What is the point of all of us sitting in this chamber and voting on debates and the Prime Minister thinks she can ignore parliamentary sovereignty?”

The Nationalist leader added: "If this Prime Minister is telling the people of Scotland that our votes don't count when we voted to Remain, we know what the answer is; the day is coming that the people of Scotland will vote for independence and we will be an independent country in the European Union."

When Mrs May referred to the 2014 Scottish independence referendum, Mr Blackford shouted out: "Give it a rest."

The PM responded by saying: "He stands up here proclaiming the benefits of democracy and yet tells me to 'give it a rest' when I point out that the people of Scotland voted to remain part of the United Kingdom."

She insisted Commons votes did matter, stressing: "But so do the votes of 17.4 million people who voted to leave the European Union."