The leader of Britain's opposition Labour party Jeremy Corbyn will warn the EU's Brexit chief Michel Barnier of the dangers of a "no deal" Brexit when he visits Brussels on Thursday (27 September), his party said.
Negotiations on future relations between the United Kingdom and the bloc have faltered, largely due to divisions within May's Conservative government over how close an economic relationship to seek with EU.
We believe a no-deal is not good for Britain; Theresa May's motion is not good for Britain; a single market is the only Brexit that has a chance of delivering for working people.
Shadow chancellor John McDonnell has argued it should be asking the public if they want to accept May's deal, while shadow Brexit secretary Keir Starmer won a standing ovation for telling conference that remaining in the European Union would be an option.
"If parliament rejected May's Chequers deal, named after the prime minister's country residence where she hashed out a plan with her ministers, the party would press for a general election", he repeated Labour's argument.
Corbyn, himself previously a euro-sceptic, has been criticised by the pro-remain camp who say he did not campaign hard enough against a Brexit vote.
Labour appears set to reject Theresa May's Brexit plan, claiming it fails to meet the party's tests for any deal.
Under the terms of the motion set to be voted on at the conference on Tuesday, if Labour can not force an early general election it will "support all options remaining on the table, including campaigning for a public vote".
Wrapping up the Labour party's annual conference in Liverpool on Wednesday, Corbyn sought to play down his own party's divisions over Brexit and presented a "radical plan" for government.
Labour's position leaves the prime minister brutally exposed to a rebellion by restive Tory backbenchers, with fewer than a dozen able to fracture her fragile control of the Commons in the upcoming vote.
He said: "That is our party policy and has been for over a year".
She rejected the argument put forward by Brexit purists that adopting a common rulebook with the European Union would stop Britain striking new trade deals.
This was a clear contradiction of John McDonnell, the Shadow Chancellor, who appeared to suggest earlier in the week that any referendum choice should be between any agreement that Mrs May strikes with the European Union or no deal.
Tuesday's agenda will be dominated by Brexit, and whether the party should opt for a second referendum, a so-called people's vote on a final deal with Brussels, or Corbyn's preferred option of a snap general election. "I am less optimistic now", he said.
"If she gets us to that chaos where there is "no deal", that there is no agreement in the British Parliament and we are heading off the cliff of "no deal", then it is absolutely right that she should make way". "Think of it as a solidarity fund for those with two homes to help those without any home at all", he said, having told the conference that one in five homes in England were now unfit for human habitation, with 120,000 children living in temporary accommodation.