The Labour Party has announced it will back a second referendum to prevent a “damaging Tory Brexit” if its withdrawal plan is rejected by MPs this week.
Jeremy Corbyn said he would put forward or support an amendment in favour of a public vote to stop Theresa May’s deal being “forced on the country” if his Brexit demands are not met.
The move came as pressure mounted on Theresa May to rule out a no-deal Brexit after three ministers threatened to support a fresh attempt to extend Article 50 and stop Britain being “swept over the precipice on March 29”.
Richard Harrington, Claire Perry and Margot James signalled their support for an amendment, drawn up by Labour’s Yvette Cooper and Tory Sir Oliver Letwin, which would give the Commons the power to demand a delay to Brexit if an agreement is not in place by March 13.
Writing in the Daily Mail, they said: “It is a commitment that would be greeted with relief by the vast majority of MPs, businesses and their employees. We implore the Government to take that step this week.
“But if the Prime Minister is not able to make this commitment, we will have no choice other than to join MPs of all parties in the House of Commons, including fellow ministers, in acting in the national interest to prevent a disaster in less than five weeks’ time that we may regret forever.”
There was speculation that as many as 15 ministers could be prepared to join them as patience among MPs opposed to no-deal is stretched to breaking point.
The Mail claimed the Prime Minister was preparing to bow to their demands and rule out a no-deal Brexit.
Mrs May will address MPs on Tuesday afternoon ahead of another series of Brexit votes on Wednesday.
The Government is expected to publish previously unseen Cabinet papers setting out the dangers of a no-deal Brexit before the debate.
Meanwhile, British negotiators will return to Brussels on Tuesday to continue talks to secure changes to the Withdrawal Agreement.
On Monday night, Mr Corbyn told a heated meeting of the Parliamentary Labour Party (PLP) that his party would seek to enshrine its five Brexit demands in law by tabling an amendment to the Government’s motion this week.
But if the plan is rejected, Labour will then support a second referendum.
Mr Corbyn also said his party would back the Cooper-Letwin amendment, and told the PLP: “One way or another, we will do everything in our power to prevent no-deal and oppose a damaging Tory Brexit based on Theresa May’s overwhelmingly rejected deal.
“That’s why, in line with our conference policy, we are committed to also putting forward or supporting an amendment in favour of a public vote to prevent a damaging Tory Brexit being forced on the country.”
A Labour source heavily hinted that a remain option would be on the ballot paper in a second referendum, saying: “We’ve said in the past that if there were another referendum that remain would need to be on the ballot paper.”
Labour’s move follows a week which saw eight of the party’s MPs quit to join the Independent Group, citing Brexit as a key concern.
One of its members, Chuka Umunna, said the referendum announcement was “better late than never”.
He told BBC Two’s Newsnight: “There’s been time-wasting on an industrial scale by both front benches in the House of Commons and it’s symptomatic of our broken politics.
“But it’s welcome that the party seems to have moved in the right direction – it’s a shame it took the departure of eight Labour MPs to help nudge it over the line.”