Theresa May has said it is “impossible” for the Government to rule out a no-deal Brexit.
In a letter to Jeremy Corbyn, the Prime Minister said it was “not within the Government’s power” to guarantee no-deal, as this could be done only by securing Parliament’s approval for a withdrawal agreement or by overturning the result of the 2016 referendum, something she was not prepared to do.
The Labour leader has snubbed talks offered by Mrs May to parliamentarians from all sides of the Brexit debate following the humiliating rejection of her Brexit deal in the House of Commons on Tuesday.
A number of Labour MPs defied a request from Mr Corbyn not to engage in discussions designed to find a plan which might command a majority in the House of Commons.
All the other party leaders have now met the Prime Minister to discuss Brexit since she survived a no-confidence vote on Wednesday evening.
Mrs May has indicated that she is sticking to the “principles” behind her Withdrawal Agreement, of taking control of money, borders and laws and having an independent trade policy.
The EU’s chief negotiator Michel Barnier indicated that Brussels was ready to respond to any revision of Mrs May’s demands, telling MPs in Portugal: “If those red lines move, we will also move, immediately.”
MPs attending the talks in the Cabinet Office and Downing Street were shown a civil service assessment suggesting it would take more than a year to stage a second EU referendum, and Mrs May made clear that a public vote was not Government policy.
The discussions took place as a new opinion poll showed a 12-point lead for staying in the EU if a fresh vote was held.
The YouGov survey for the People’s Vote campaign, conducted after Mrs May’s Brexit plan went down to a humiliating 230-vote defeat in the House of Commons, put Remain on 56% against 44% for Leave.
Meanwhile, it was announced that military reservists have been put on standby for up to a year of permanent service in to handle the possible fallout from a no-deal Brexit.
Reservists will make up around around 10% of the 3,500 armed forces personnel held at readiness ahead of the scheduled Brexit date on March 29.
Speaking in the marginal Conservative seat of Hastings, Mr Corbyn dismissed the cross-party discussions as a “stunt” and said the PM seemed unable to grasp the fact that her Withdrawal Agreement was now “dead”.
“She seems to be prepared to send the country hurtling towards a cliff edge,” said Mr Corbyn.
“To get a deal that can command a majority in Parliament, Theresa May has to ditch the red lines and get serious about proposals for the future.”
Mrs May insisted her door remained open for talks with the Labour leader, but told him: “That is an impossible condition because it is not within the Government’s power to rule out no deal.”
There was little sign of movement as a series of parliamentarians from both Leave and Remain camps emerged from talks conducted by Mrs May herself, Brexit Secretary Stephen Barclay and Cabinet colleagues Michael Gove and David Lidington.
Number 10 said that the Prime Minister was “in listening mode” and wanted to hear views and opinions from every side of the debate before drawing up the Plan B which she is due to present to Parliament on Monday.
The PM’s motion, and any amendments tabled by MPs, will be the subject of the latest in a series of crunch Brexit votes in the Commons on January 29.
The one-page document shown to MPs, entitled “referendum timings”, said that seven months would be needed to pass primary legislation paving the way for a new poll, followed by 12 weeks for a question to be tested and selected, six weeks for secondary legislation, six weeks to designate lead campaigns and 10 weeks for the campaign.
But former attorney general Dominic Grieve, a supporter of the People’s Vote campaign, said the suggested timetable was “simply wrong”.
“If Parliament wishes to have a referendum and the Government is prepared to facilitate it, it could be carried out swiftly and within a limited time extension of Article 50,” he said.
“It is neither helpful nor right to have misleading information of this kind put out.”
Emerging from Downing Street, Democratic Unionist Party leader Arlene Foster said the issue of the Irish backstop needed to be dealt with “in a very clear way” if Brexit negotiations were to make progress.
Green MP Caroline Lucas said the Prime Minister had shown little sign she was ready for compromise on the Withdrawal Agreement she reached with Brussels in November.
“I’m not convinced she’s willing to loosen any of the red lines she’s set herself,” Ms Lucas said.
“She still thinks it’s going to be possible to tweak this deal sufficiently to get the MPs that voted against it to swing behind it – I remain pretty sceptical about that.”
Speaking after a meeting with Mr Lidington, Labour MP Yvette Cooper said: “The most important thing now is that the Government actually listens and it doesn’t just think that a defeat that was that huge can simply be dismissed.”
She and fellow Labour MP Hilary Benn said they had attended in their capacity as parliamentary committee chairs.
Labour’s former prime minister Tony Blair said Mr Corbyn was wrong to refuse to meet Mrs May.
“If, in a moment of national crisis, the Prime Minister asks the Leader of the Opposition to come and talk, of course he should,” Mr Blair told BBC Radio 4’s Today programme.
Conservative chairman Brandon Lewis accused Labour of “trying to frustrate and avoid Brexit”.
Sir Vince Cable, who spoke with Mrs May on Wednesday evening, accused Mr Corbyn of playing “party political games” and said the Liberal Democrats would no longer join Labour in no confidence votes in the Government.
“I believe other parties are taking the same view,” the Lib Dem leader said.
“It’s time Mr Corbyn got off the fence and made his position plain.”
Lib Dems said they used a meeting on Thursday to press the case for a second referendum.
“The Government now needs to get serious about making significant changes to their own position,” a spokesman said.
“The ball is ultimately in their court.”
A Conservative Right To Vote campaign for a second EU referendum was launched by MP Phillip Lee, who claimed support for a so-called People’s Vote was “growing fast” among his colleagues on the Tory benches.