Boris Johnson’s plan to take Britain out of the EU on October 31 will on Saturday face its moment of truth, as Conservative grandees prepared to join forces with Labour to derail the prime minister’s freshly minted Brexit deal.
With hundreds of thousands of protesters expected in Westminster to demand a second EU referendum, the stage is set for a “super Saturday” in which Mr Johnson faces knife-edge House of Commons votes to push ahead with Brexit.
But before he can get to the crucial vote on his Brexit deal he must first overcome a new hurdle erected by Tory grandee Oliver Letwin and former cabinet ministers including Philip Hammond and David Gauke.
The Letwin amendment, also backed by Labour, would defer full parliamentary approval of Mr Johnson’s deal until the relevant implementing legislation is passed. Mr Johnson would then have to write a letter to the EU seeking a Brexit delay.
Although Mr Johnson could still press ahead to try to ratify the Brexit legislation — the Withdrawal Agreement bill — by October 31, the Letwin amendment would open the door to much lengthier parliamentary scrutiny and a likely delay to Britain’s exit.
Mr Johnson arrived back from a Brussels summit in the early hours of Friday morning — having secured the EU’s backing for a Brexit deal — and spent a frenetic day urging Conservative and Labour MPs to join him in “getting Brexit done”.
Mark Carney, the Bank of England governor, predicted on Friday the UK economy would pick up if MPs voted for the Brexit deal, adding that resolving Brexit might also help lead the world out of its current tensions over trade.
Downing Street was confident it could win the backing of most or all of the 28 Brexiter Tory rebels who defeated Theresa May’s deal, while 10 Labour MPs also endorsed the new deal, pushing Mr Johnson closer to the 320 votes he needs for victory.
John Baron, a Tory Brexiter, said he would back Mr Johnson’s deal because he had been assured by cabinet minister Michael Gove that Britain could still leave the EU without a deal if no trade deal was in place by the end of a transition period in 2020.
Mr Hammond, the former Tory chancellor, wrote in the Times that he would only vote for the deal if Mr Johnson promised this was not his intention. He said he would not be “duped into voting for a heavily camouflaged no-deal at the end of 2020”.
Meanwhile Mr Johnson offered new guarantees that Britain would uphold high employment standards after Brexit — and new legislation to protect new staff at companies from wrongful dismissal — to win over more Labour MPs from Leave areas.
Labour MPs have been told by Jeremy Corbyn that they will not be punished if they defy the party whip and back Mr Johnson’s Brexit plan, which includes the introduction of a new customs border between Northern Ireland and the rest of the UK.
With Northern Ireland’s Democratic Unionist party refusing to back the deal, Mr Johnson spent Friday trying to win every vote. Aides said he was using all of his powers of patronage and persuasion to win over waverers.
The prime minister was helped by Emmanuel Macron, French president, who raised the pressure on MPs by suggesting the EU would not accept any further delay. “I don’t think a new extension should be granted,” he said.
Although many MPs believe that Mr Macron is bluffing and that the EU will ultimately support a Brexit extension to avoid the chaos of a no-deal Brexit, the French president has provided valuable cover to Labour MPs.
Sarah Champion, Labour MP for Rotherham, said she would back Mr Johnson’s deal because it was “unlikely the EU would grant a further delay” and that the choice was between Mr Johnson’s deal and “a catastrophic no-deal”.
Mr Johnson told ITV News that the country would “heave a huge sigh of relief” if Brexit was completed, but two predecessors in Number 10 — Tony Blair and John Major — issued a joint warning that his plan could lead to the break-up of the UK.
In a video to be shown at the People’s Vote march in London on Saturday, they also called for a second referendum on the deal.
Mr Blair said it was an “outrage” that peace in Northern Ireland was being treated as “some disposable inconvenience to be bartered away in exchange for satisfying the obsession of the Brexiteers with wrenching our country out of Europe”.
Additional reporting by Michael Peel in Brussels and Chris Giles in Washington