MPs are making a cross-party bid on Wednesday to seize control of the Commons agenda to prevent the next Tory prime minister forcing through a no-deal Brexit.
The binding motion, tabled by Labour leader Jeremy Corbyn and backed by senior figures including Tory grandee Sir Oliver Letwin and Liberal Democrat leader Sir Vince Cable, would see MPs hijack the parliamentary timetable on 25 June, allowing them to introduce legislation to rule out no deal and bar a PM from using prorogation – the suspension of parliament.
Their intervention comes as the frontrunner, Boris Johnson, in the Tory leadership race renews his pledge to take the UK out of the EU by 31 October with or without a deal.
The presence of Sir Oliver’s name on the order paper will embolden some Tory MPs to take the unusual step of backing a Labour opposition day motion.
Even the cabinet minister and leadership candidate Rory Stewart initially suggested his “instinct” was to support it, though he later clarified that he would not vote with Labour on Wednesday.
Breaking cover for the formal launch of his leadership bid on Wednesday, Mr Johnson will warn that “kicking the can down the road” would usher in a Labour government and threaten the Conservative Party’s survival.
“Delay means defeat. Delay means Corbyn,” he will say. “Kick the can and we kick the bucket.”
Ex-Brexit secretary Dominic Raab provoked outrage when he mooted suspending parliament to prevent MPs from blocking Brexit, and Esther McVey, the former work and pensions secretary, has not ruled it out.
And the former Commons leader Andrea Leadsom said that she would be ready, as prime minister, to ditch her planned Brexit bills in order to stop MPs from amending them to delay EU withdrawal beyond 31 October.
The shadow Brexit secretary Sir Keir Starmer said: “The debate on Brexit in the Tory leadership contest has descended into the disturbing, the ludicrous and the reckless.
“None of the likely candidates for the top job has a credible plan for how to break the deadlock before the end of October.
“Instead, we have witnessed candidates openly advocating a damaging no-deal Brexit and even proposing dragging the Queen into politics by asking her to shut down parliament to achieve this.
“MPs cannot be bystanders while the next Tory prime minister tries to crash the UK out of the European Union without a deal and without the consent of the British people.”
Breaking cover with his first appearance of the leadership campaign, Mr Johnson will say the government must deliver withdrawal in order to start the process of healing the divisions left by the 2016 referendum
“Now is the time to unite this country and unite this society, and we cannot begin that task until we have delivered on the primary request of the people, the one big thing they have asked us to do,” Mr Johnson will say. “After three years and two missed deadlines, we must leave the EU on 31 October.
“With every week and month that goes by in which we fail to deliver on our promise, I am afraid we will further alienate not just our natural supporters but anyone who believes that politicians should deliver on their promises.”
But his leadership rival Sajid Javid will deliver a barely veiled challenge to Mr Johnson’s fitness for the PM’s role, saying Tories “can’t risk going with someone who feels like the short-term, comfort-zone choice”.
Mr Johnson also came under fire from Mr Stewart, who said Conservative members should ask themselves: “Do you really feel that this is the person that you want engaging in the detail of the future of your health and education, is this the person that you want writing the instructions to your nuclear submarines, is this the man that you want embodying your nation on the world stage and guiding you through the most difficult choice that Britain has faced for 50 years?”
And he added: “I trust the Conservative members to arrive at the correct answer.”
The cross-party motion has been tabled as a Labour opposition day debate, but unlike typical opposition sessions, it will be binding on the government if it is passed.
Also backed by the SNP, Lib Dems, Plaid Cymru and Greens, it clears the agenda on 25 June, giving MPs the chance to introduce measures to prevent a no-deal exit.
This could involve setting a date in the future when MPs must be given a vote on whether to go ahead with the deal on offer.
Launching his own leadership bid, Mr Javid will say he offers “a new kind of leadership and a new kind of leader”.
Recalling the revival in Scottish Conservative fortunes after they “threw out central casting and picked someone totally different” in Ruth Davidson as leader, he will say: “A leader is not just for Christmas, or just for Brexit. We need tomorrow’s leader, today.”
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