Tom Watson will claim the result of the 2016 vote to Leave is “no longer a valid” because it took place nearly four years ago. He will say there is “no such thing as a good Brexit deal” and the Opposition’s top priority must be stopping the country leaving without a withdrawal agreement.
Labour must push for a referendum before any election but if there is a snap poll it should “unambiguously and unequivocally back Remain”, Mr Watson will say in a speech in London.
Prime Minister Boris Johnson accused Labour of running scared “because they fear that their party will lose” when it refused to back an early election on Monday.
Mr Watson will claim going to the polls would not break the Brexit deadlock and insist that while a vote “might at this moment seem inevitable, but that doesn’t make it desirable”.
He will say: “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.”
“If there is still a majority for Brexit, what do they have to fear?” he will add. “If there isn’t any more, how can it then be democratic to leave, just because there used to be a majority for it more than three years ago, when so many things were so different?”
It comes after Jeremy Corbyn claimed an “election is coming” despite blocking a snap poll just 24 hours earlier.
At a conference of union barons, the Labour leader insisted his party was “ready” and vowed to campaign for a second referendum.
Mr Corbyn told the TUC he refused to agree to give voters a say because he did not want to allow Mr Johnson to “dictate” the terms.
A Labour government would force the country to vote again on Brexit but the ballot paper would not contain any option for leaving without a deal, he said.
He said: We’re ready for that election. We’re ready to unleash the biggest people-powered campaign we’ve ever seen.
“And in that election we will commit to a public vote with a credible option to leave and the option to remain.”
Mr Corbyn also claimed would put power “in the hands of workers” under plans for major expansion of employment rights.
He said: “The next Labour government will bring about the biggest extension of rights for workers that our country has ever seen. We will put power in the hands of workers.”
A Labour government would set up a Ministry for Employment Rights and give employees more of a say over how their workplaces are run, he said.
James Cleverly, Conservative Party Chairman, said: “Labour’s Deputy Leader makes clear Labour want to cancel the referendum result.
“This latest trick would mean delaying Brexit again for up to a year, handing over £250 million a week to Brussels for no purpose. Labour are running scared of an election and only offer more dither and pointless delay.
“Only Boris Johnson and the Conservatives will deliver Brexit by 31 October, no ifs or buts, so we can move on and focus on the issues that matter to people – investing in the NHS, reducing violent crime and cutting the cost of living.”