Two of Labour's most senior figures have triggered a furious new Brexit row within their own party claiming a second EU referendum is the only way to break the deadlock.
In a move that will anger Labour MPs from Leave constituencies, deputy leader Tom Watson and shadow Brexit secretary Sir Keir Starmer stepped up demands for a fresh public vote on Brexit.
In a speech in London on Wednesday, Mr Watson - already a hate figure for many allies of Labour leader Jeremy Corbyn - demanded a referendum before a general election.
Mr Watson declared: "Boris Johnson has already conceded that the Brexit crisis can only be solved by the British people.
"But the only way to break the Brexit deadlock once and for all is a public vote in a referendum.
"A general election might well fail to solve this Brexit chaos."
Mr Watson said that once parliament resumes in October, its first priority must be to stop a no-deal Brexit.
But once it has done that, MPs should focus on securing a referendum before an election.
Meanwhile, at the Trades Union Congress (TUC) conference in Brighton, Sir Keir also argued a public vote is the only way to overcome the Brexit impasse.
In what looks like a co-ordinated move with Mr Watson, he said: "We will have to break the deadlock.
"And clean up the mess left by the Tories. A referendum is the only way to do so.
"And that is why Jeremy was right to say at Congress yesterday that an incoming Labour government will commit to a referendum."
In his own speech in Brighton on Tuesday, Mr Corbyn said Labour would commit to a public vote during the next general election campaign "with a credible option to Leave and the option to Remain".
While Sir Keir is careful to back Mr Corbyn, Mr Watson's demand will be seen by his critics in the party and Corbyn allies as a challenge to the Labour leader's authority.
Mr Watson said that a "Brexit election" might at the moment seem inevitable, but warns: "That doesn't make it desirable. Elections should never be single-issue campaigns."
He said the scale of the damage Mr Johnson is threatening the country with is "worse than Thatcher" and claim the prime minister has "naked contempt" for democratic institutions - not just the EU, but parliament, the British constitution and the Conservative Party.
"He's trying to trash them all," he added.
Hitting back at Mr Watson, Tory chairman James Cleverly said: "Labour's deputy leader makes clear Labour wants to cancel the referendum result.
"This latest trick would mean delaying Brexit again for up to a year, handing over £250m a week to Brussels for no purpose.
"Labour are running scared of an election and only offer more dither and pointless delay."
In his TUC speech, Sir Keir warned Mr Johnson that Labour will not be silenced in its opposition to a no-deal Brexit.
He said: "Prime Minister Johnson now thinks that by shutting down parliament he will shut us up.
"Nothing could be further from the truth.
"Just as we worked throughout the summer to pass a law preventing no-deal, so we will work each and every day we are shut down to enforce that law.
"Prime minister: you can hide from parliament for a few weeks, but when we return we will be ready."
On a general election, Sir Keir said: "We have to stop no-deal. Last week - we beat them in parliament.
"But very soon we will have to beat them at the ballot box.
"Brexit will of course be a crucial issue at this election. We have to draw a line under the wasted years of Tory rule and failed negotiations."