Labour could bring down the government in an effort to block a no-deal Brexit.
The party has declared “no deal is not an option” despite refusing to support the Prime Minister’s withdrawal plan.
Keir Starmer MP, Shadow Brexit Secretary, told a meeting of the Parliamentary Labour Party he is prepared to work with MPs from across the Commons to prevent the UK crashing out of the European Union without a deal.
Labour would be prepared to use any parliamentary measures at its disposal, including tabling a motion of no confidence in Theresa May’s Government.
If she loses, a new government would have to be formed within 14 days and win a confidence vote in the House of Commons.
If the new administration could not do so then there would be a general election.
Speaking to the Confederation of British Industry Labour leader Jeremy Corbyn said: “The choice between Theresa May’s deal and no deal is a false choice, designed to scare people into backing the Government.
He added that: “Labour has set out an alternative plan for a sensible jobs-first agreement that could win support in parliament and help bring our country together.”
Sir Keir was expected to tell the meeting of the PLP on Monday: “The deal the Prime Minister has brought back is a miserable failure of negotiation. It falls far short of a deal Labour could support.
“If Theresa May’s deal fails to command the support of Parliament, then we will not stand back and allow her to take this country off a cliff.
“No deal is not an option. Labour will not countenance no deal – and nor would many of the Prime Minister’s own MPs.
“It would be politically unsustainable for any government to deliver a no deal without the consent of Parliament.
“There will be opportunities to make the majority against no deal heard. Motions will be tabled, amendments will be pressed and a no-confidence vote can be triggered.
“And let me be clear: Labour will work with all sides to make that happen.”
The Opposition could use the passage of legislation required in advance of Brexit to table amendments aimed at ruling out a no-deal departure.
Labour could also use the time it is allocated for opposition day debates to attempt to win support for its position.