Theresa May has warned MPs unhappy with her Brexit deal that it is too late for the UK to go back to Brussels to re-negotiate the agreement.
The Prime Minister is facing demands from MPs across the political spectrum to abandon her plan and go back to the negotiating table.
However in a BBC phone-in as part of her drive to sell the agreement to the public, Mrs May insisted there is no mood on the EU side for fresh concessions.
“If we were to go back to the European Union and say ‘People didn’t like that deal can we have another one?,’ I don’t think they are going to come to us and say ‘We will give you a better deal’.
“This is the deal that I think works for the UK,” she said.
Earlier, former Brexit secretary Dominic Raab, a committed Leaver who quit last week over the Withdrawal Agreement, said he believes the terms are so bad the UK would be better off remaining in the EU.
“I’m not going to advocate staying in the EU,” he told the BBC Radio 4 Today programme.
“But if you just presented me terms, this deal or EU membership, because we would effectively be bound by the same rules but without the control or voice over them, yes, I think this would be even worse than that.”
With more than 80 Conservative MPs - from both the Leave and Remain sides - threatening to vote against the agreement, Mr Raab warned it is unlikely to get through the Commons and said ministers should consider leaving without a deal.
“We will, I think, inevitably see Parliament vote this deal down. And then I think some of those other alternatives will need to come into play,” he said.
Mrs May, however, warned rejection of her plan would lead to more “uncertainty and division” and that the public now wants the Government and MPs to get on and deliver Brexit.
“In Parliament there’s a lot of focus on who’s going to vote for the deal or not, and outside I think people are thinking ‘Actually, let’s make sure we can get this through and get on with delivering’,” she said.
“If this deal doesn’t go through we are back at square one. What we end up with is more uncertainty and more division.”
Despite the turmoil, the Prime Minister again insisted that as far as she is concerned, Brexit will go ahead next year as planned.
“Personally there is no question of no Brexit because the Government needs to deliver on what people voted for in the referendum in 2016,” she said.
“As far as I am concerned, the UK is leaving the European Union on March 29 2019.”
The latest clash came as Mrs May was warned she faces a battle to reach a final agreement on her deal at a special summit of European Union leaders on Sunday.
Spanish premier Pedro Sanchez demanded last-minute changes to the deal to reflect Spain’s continuing concerns over the status of Gibraltar.
Mrs May said she spoke to Mr Sanchez on Wednesday night and is “confident on Sunday that we’ll be able to agree a deal that delivers for the whole UK family, including Gibraltar”.
But in a late-night tweet on Thursday, Mr Sanchez said: “After my conversation with Theresa May, our positions remain far away.
“My Government will always defend the interests of Spain. If there are no changes, we will veto Brexit.”
Mr Sanchez cannot “veto Brexit” or the Withdrawal Agreement, but a refusal to co-operate will sour the atmosphere at a summit where leaders of the 27 remaining EU members are aiming for consensus.
Marco Aguiriano, Spain’s state secretary for European affairs, said Madrid needs “guarantees we can go on with this model”.
He told the BBC: “We are asking for an article that is put on the table to be included in the Political Declaration on the future relations.”
Downing Street said it is “not aware” of any moves to add any appendix or addendum to the Withdrawal Agreement to deal with other nations’ concerns over issues including Gibraltar or fishing.
A spokeswoman said: “The Withdrawal Agreement isn’t being reopened.”
Chief Minister of Gibraltar Fabian Picardo criticised Spain’s stance.
He told the BBC: “Spain doesn’t need an article in the treaties, the future declaration, or indeed the Withdrawal Agreement, to bring Gibraltar to the table.
“Gibraltar has demonstrated that we actually want a direct engagement with Spain on issues.”