Labour leader says ‘put all options on the table’ including a people’s vote if no general election is possible

Jeremy Corbyn called on MPs of all parties to vote down Theresa May’s deal and back his alternative plan for Brexit, as campaigners for a second referendum urged him to get “off the fence” and endorse a fresh public vote.

Labour’s leader, writing in the Guardian, said that the party’s “comprehensive customs union plan” should be one of the options on the table if the party could not force a general election – in addition to a second referendum.

Corbyn argued that if May was defeated next Tuesday the government would lose “its ability to govern”. That would have meant an automatic election before the introduction of the Fixed Term Parliaments Act in 2011, which formalised the rules governing votes of confidence.

“If under the current rules we cannot get an election, all options must be on the table,” Corbyn wrote. “Those should include Labour’s alternative and, as our conference decided in September, the option of campaigning for a public vote to break the deadlock.”

Labour sources said recent polling showed that the most popular option with the British public was trying to renegotiate the Brexit deal, although the party wants to retain maximum flexibility in what is likely to be a chaotic period if May’s deal is, as is widely expected, voted down.

The careful positioning came as it emerged that a head-to-head TV debate between Corbyn and May would almost certainly not take place after ITV announced it had abandoned its plan to broadcast it because Labour and the Tories could not agree on its format. The decision followed the BBC dropping its own plans for a similar programme.

However, Labour’s decision to maintain its “constructive ambiguity” over Brexit and support a range of options came under fire from frustrated second-referendum campaigners on Thursday, one of whom abandoned her plan to submit an amendment to next week’s final vote on Thursday.

Tory MP Sarah Wollaston, a former GP, had planned to put down a cross-party “doctor’s amendment” calling for a second referendum, but said she would not do so because she had been persuaded that without Labour frontbench support at this stage it would be at risk of heavy defeat.

Wollaston said that she made her decision after discussions with the people’s vote second-referendum campaign, many of whose active members included backbench Labour MPs such as Chuka Umunna and Chris Leslie. “Labour has to end the constructive ambiguity, Corbyn has to come off the fence,” Wollaston added.

She said that she would make her move after May’s deal “failed in the Commons”, although last night the Liberal Democrats took advantage of Wollaston’s decision to submit their own amendment instead.

The Lib Dem amendment instructs the government “to take all necessary steps to prepare for a people’s vote” although the party’s small number of MPs in the Commons means it will have no chance of passing it next week.

Corbyn said that as part of Labour’s “alternative plan” he wants to strike a “comprehensive customs union with the EU, with a British say in future trade deals”. He added that he wants the UK to enjoy “a new and strong relationship with the single market that gives us frictionless trade” – although with time running out before Britain is due to leave the EU in March 2019 it was unclear how the plan could be negotiated.

Corbyn also came out against the unpopular customs backstop in an effort to woo pro Brexit voters, warning that if the UK used it “workers’ rights would be allowed to fall behind” and “restrictions on state aid to industry would be locked in”.

The article came a day after it emerged that the Labour’s powerful union backer, Len McCluskey, had warned Labour MPs in a private meeting that they should have reservations about a second referendum.

One person present said that McCluskey had warned that there would be “a sense of betrayal” if the party chose that option, although the issue is divisive at senior levels of the party. Over the weekend it emerged that Sir Keir Starmer, Labour’s Brexit spokesman, had wanted Labour to quickly get to the point where a second referendum became an option.

In September Labour adopted a compromise position in which the party would first decide whether to oppose May’s deal, then, if it was voted down, try to force a general election, before turning to other options. But with the vote looming, Corbyn and the party’s leadership is coming under pressure to spell out what it might do next.

Tony Blair, the former prime minister and campaigner for a second referendum, returned to Westminster on Thursday to say he believed that May’s “half in and half out” deal satisfied no one in the Brexit debate and that there was no solution that commanded majority support in the House of Commons either.

Speaking at a parliamentary press gallery lunch, Blair said that MPs could be obliged to consider a second referendum. “My guess, and I may be 100% wrong, is that when all the options are voted upon, parliament will come to the view that none can truly be said to reflect the majority will of the people, and it’s back to them therefore that we must go for resolution.”

If May’s deal is defeated in the Commons on Tuesday Corbyn could call for a vote of no confidence on Wednesday. However, Labour is desperate to avoid signalling its intentions until the last minute.

Under the Fixed Term Parliaments Act, if May is defeated by one vote, her government will fall, but there will be 14 days in which an alternative government could be formed.

Corbyn flies to Lisbon on Friday for the two-day congress of the Party of European Socialists. Party sources said he was expected to meet Frans Timmermans, a European commission vice-president who is the socialists parties’ candidate for the commission presidency, to press his case.