Senior Labour figures have warned a cross-party Brexit deal will be "impossible" to get through the Commons unless it includes a fresh public vote.
In an escalation of pressure on Labour leader Jeremy Corbyn, both shadow Brexit secretary Sir Keir Starmer and deputy leader Tom Watson said up to 150 of the party's MPs could oppose any deal without a Final Say vote attached.
It comes as cross-party talks enter their seventh week, with pressure on both Theresa May and Mr Corbyn to walk away from the negotiations.
The latest session of talks began on Monday evening, with patience wearing out in the Tory ranks about Ms May's leadership and the attempt to strike a deal with Mr Corbyn's party.
Downing Street said the talks, which began in early April, had been "serious" but "difficult".
Asked if Monday's meeting between the negotiating teams was the "last chance" to make progress, the Prime Minister's official spokesman said: "Let's see how this evening plays out."
Foreign secretary Jeremy Hunt said this week would be "crunch week" for the cross-party negotiations, adding that another public vote "would be a betrayal of what people voted for, and we want to implement the first referendum".
This liveblog has now closed, but you can see Monday's events below
He told BBC Radio 4's Today programme: "The difficulty is just parliamentary arithmetic and Keir Starmer (the shadow Brexit secretary) has alluded to this today as well, and John McDonnell did last week.
"The whipping arrangements for these deals is very difficult because MPs have hardened their positions within their parties so I think it would be very difficult."
Mr Watson continued: "If a deal could be found that inspires enough votes in Westminster then fine, but it seemed to me that that's very, very difficult.
"And so my idea of a confirmatory ballot is not a religious point or a point of ideology, it's just how do you get an outcome, how do you sort this out?
"And one way to do it are these two minority positions - the Prime Minister's deal and those that think the people should have a say on the deal - plug them together and you build a majority."
"We are remain and reform party but obviously when it comes to a deal people can form their own view," he told Today.
"But when it comes to that European election let me just say Remain is not on the ballot paper in that election."
Interesting...
His shadow cabinet colleague Richard Burgon said Labour "doesn't exist to stop Brexit" only a few days ago.
Keir Starmer has said up to 150 Labour MPs would vote against any cross-party Brexit deal which excluded a second referendum.
The Holborn and St Pancras MP has been involved in Labour’s Brexit talks with the government but said a deal which failed to include a confirmatory public vote was unlikely to pass in the Commons.
“A significant number of Labour MPs, probably 120 if not 150, would not back a deal if it hasn’t got a confirmatory vote,” he told The Guardian.
More here:
Almost three-quarters of voters think the government has spent too much time on Brexit at the expense of addressing other important issues, a new poll had found.
The BMG survey for The Independent found that 74 per cent of voters thought ministers had “forgotten” about important domestic issues and focused too much attention on negotiating Britain’s EU withdrawal.
36 per cent said they strongly agreed with the suggestion, while a further 38 per cent somewhat agreed.
"People have been pessimistic right from the outset that these discussions weren't going to go anywhere, but they have actually continued.
"So we have to see what happens this week. This is a crunch week."
On the possibility of a second referendum on Brexit, Mr Hunt added: "From a Conservative point of view, we've always said that we think that would be a betrayal of what people voted for, and we want to implement the first referendum.
"But let's see where these talks go to."
The Conservatives have plummeted to fifth place in the latest poll ahead of the European elections, 24 points behind the buoyant Brexit Party.
The survey ahead of next week’s contest has the Tories on just 10 per cent, securing less backing than Labour, the Liberal Democrats and the Green Party.
However, Nigel Farage’s newly-formed Brexit Party was in the lead, which despite only being launched weeks ago was on 34 per cent in the YouGov poll for The Times.
Nigel Farage has been banned from his local pub after the landlord accused him of walking away from the scene of a head-on car crash.
The Brexit Party leader was being driven to a campaign event when his Range Rover collided with Patrick Tranter’s Jaguar on a narrow country lane in Kent.
Mr Tranter, who was with his one-year-old son, claimed the MEP quickly left without checking if anyone was hurt.
Editorial: Even if the Brexit Party succeed at the European elections, it'll have no impact on Brexit
"Even if Nigel Farage won every single vote, he could not guarantee frictionless trade, he could not prevent a post-Brexit recession, and he could not solve the Irish border riddle. Nor could any other politician."
The staunch Brexiteer said he did not "see how a leader can go on" with so little support from party faithful, saying Ms May had lost the backing of Conservative associations across the country.
As a remarkable new poll put the Conservatives in fifth place in the upcoming European elections, Mr Rees-Mogg said the activists he was meeting were saying they would vote for Nigel Farage's insurgent outfit.
Pressed on whether firms should be stockpiling for the possibility of a no-deal outcome in October - the new Brexit deadline - the PM's spokesman would not be drawn, but said it was a matter of legal fact that a deal Brexit was still the default route, without a deal in place.
"They're the worst I've seen in my political history and I've been a member of the party for 44 years.
"The fact is, what are we going to say? Please vote for our MEPs who we hope won't be able to take their seats because we will have done a deal? That's basically the message."
On the cross-party Brexit talks between Labour and the Conservatives, he added: "These talks that are resuming today between the Labour Party and the Conservatives are nothing more than a cosmetic exercise, which was displayed by Tom Watson this morning," he said.
"How can we possibly talk to a Labour Party that has its deputy leader of that party saying now they wish to remain and reform the European Union?"
Attending the launch of her party's European election manifesto in Belfast, she also criticised Theresa May for lacking the vision of a strong UK post-Brexit.
"What people want to see is democracy being respected. Unfortunately it hasn't been respected and we have a Remain parliament, therefore parliament has not been able to deliver on Brexit in the way it should have been delivered upon," she said.
"We have a prime minister frankly who doesn't have the vision for the United Kingdom post Brexit that we all want to see. We want to see a United Kingdom that is strong post-Brexit and has a close relationship with Europe."
Nigel Farage's Brexit Party would beat Conservatives in a general election, shock poll finds
Nigel Farage’s Brexit Party would win more votes in a general election than the Conservatives, a shock new poll has found.
The result would give the new party almost 50 seats in the House of Commons, transforming the political landscape amid widespread public anger at the mainstream parties’ handling of Brexit.
Tom Watson will today claim that former party leader John Smith would have understood the need for a Final Say vote.
In a speech on Monday, the party’s deputy leader will admit that Labour supporters are “not happy” with its current Brexit policy and make an impassioned plea to them not to abandon the party in European parliament elections later this month.
In comments that will be widely interpreted as on attack on Mr Corbyn, he will hit out at left-wing critics of the EU and say that they are just as “wrong-headed” as right-wing Eurosceptics.
Mr Watson will use a lecture at the Fabian Society in memory of Smith, a popular figure in Labour, to pile pressure on Mr Corbyn to back a Final Say referendum.
"If you try to insert a second referendum into these talks they won't get through because the Conservatives will not whip their MPs to support it."
