The shadow Brexit secretary has demanded a second referendum, as cross-party Brexit talks continue.
Sir Keir Starmer said it would be "impossible" for an agreement between the Conservative Party and Labour to gain the support of MPs unless it guaranteed the Brexit deal would be put back to the public for a "confirmatory vote".
He made the comments ahead of crunch talks between Cabinet ministers and senior Labour figures taking place today.
Speaking to The Guardian, Sir Keir said his colleagues and the party leadership would have to decide "in the coming days" if it was worth continuing with the talks.
"I've made it clear that at this stage, at this 11th hour, any deal that comes through from this government ought to be subject to the lock of a confirmatory vote," he said.
He added that "probably 120 if not 150" of the party's 229 MPs could vote against the deal unless it was linked to a second referendum.
"If the point of the exercise is to get a sustainable majority, over several weeks or months of delivering on the implementation, you can't leave a confirmatory vote out of the package," he said.
Chancellor Philip Hammond is said to be among those who have lost faith with the plan to strike a cross-party deal, while on Sunday, education secretary Damian Hinds expressed support for finding a "stable majority" by allowing MPs to vote on different options.