Jeremy Corbyn has challenged the next Tory leader to hold another referendum before taking Britain out of the EU, saying Labour will campaign for Remain.
Mr Corbyn says the party will take this position to stop “no deal or a damaging Tory Brexit”.
But he does not say what he would do if he won a general election and was placed in charge of the Brexit process.
Some senior members of his team want him to take a pro-Remain stance in any circumstances.
In a letter to members, Mr Corbyn said: “Whoever becomes the new prime minister should have the confidence to put their deal, or no deal, back to the people in a public vote.
“In those circumstances, I want to make it clear that Labour would campaign for Remain against either no deal or a Tory deal that does not protect the economy and jobs.”
The announcement follows a shadow cabinet meeting on Tuesday morning, and a meeting with trade union leaders on Monday.
Labour’s Hilary Benn – who chairs the Brexit select committee – was a “big step forward” and called it “significant”.
He added: “We can now see there is nothing that can be better negotiated that is better for jobs, that is better than the deal we currently have.”
