Boris Johnson today launches a frantic charm offensive in a bid to get his Brexit deal passed in the House of Commons.
The Prime Minister returned from Brussels in the early hours to start persuading MPs to back the agreement tomorrow - despite having a majority of minus 45.
MPs will hold their first Saturday sitting since the Falklands War in 1982 after the Prime Minister's new pact was backed by 27 other EU leaders last night.
In a boost to the PM, ousted Tory Oliver Letwin today said 17 or 18 of the 21 Tories who lost the whip last month were likely to back the deal in the House of Commons.
But key ally Dominic Raab admitted it will be "tight" after 10 DUP MPs vowed to vote against - and warned they will be encouraging Tory Brexiteers to do the same.
That will force the Prime Minister to rely on Labour votes if he is to have any hope of getting the deal through in Saturday's historic vote.
While some Labour MPs will back a deal, the party has warned there will be "consequences" for the few backbenchers who do - and sources are sceptical about there being more than a dozen or so.
The PM began the day with team meetings with Tory whips. He was then expected to hold a string of meetings with wavering MPs in 10 Downing Street as he attempts to persuade them to back the pact.
The Times reports efforts to win over Labour MPs are being led by Mark Spencer, the chief whip, and Danny Kruger, Boris Johnson ’s political secretary.
But those Labour MPs also face a showdown with their own Chief Whip - as Labour refuses to rule out withdrawing the whip if they back Boris Johnson.
Shadow Chancellor John McDonnell warned he'd "have a chat'' with deal-backing MP Ronnie Campbell to beg him: "Please do not give Boris Johnson this power."
A Labour source also confirmed to the Mirror that some members of Labour's ruling National Executive Committee have discussed barring deal-backing MPs from standing again in an election.
Sources insisted the idea was only in informal discussion among some members of the NEC and stressed it had not been tabled formally.
If the deal is voted down in the Commons tomorrow, it will force Boris Johnson to request a three-month delay from the EU by 11pm.
MPs today unveiled three amendments to the deal.
The most significant would refuse to approve Boris Johnson's deal in final form tomorrow - instead waiting until it's passed through its last vote next week.
Two SNP amendments will also call for a general election and revoking Article 50 to cancel Brexit.
But a bid to use Saturday's historic session to secure a second referendum appears to have been dropped - with campaigners looking to next week instead.
Labour's John McDonnell suggested a better time will be when the EU Withdrawal Act has to pass through the Commons next week.
He added: "The government has to bring forward legislation to enact this deal and therefore the timing of any proposals on amendments is critical."
Lib Dem Chuka Umunna also indicated Saturday is not the time for a second referendum vote, saying: "The focus tomorrow will be defeating the deal."
The deal is based on a new Brexit plan Boris Johnson sent the EU two weeks ago to replace Theresa May's 585-page Withdrawal Agreement.
The 64 pages of amendments would keep a transition period which continues EU rules in Britain and payments to Brussels, up to 31 December 2020.
But they would ditch the Irish backstop, an insurance policy designed at preventing a hard border from 1 January 2021, in favour of a hybrid customs territory that amounts to a border down the Irish Sea - plus Northern Ireland sharing some EU rules with the Republic.
Northern Ireland's Assembly will get a vote on the situation in late 2024 - but the DUP were left outraged after they were denied a veto in that vote.
DUP Brexit spokesman Sammy Wilson told BBC Radio 4's Today programme: "I can give you absolute assurance we will not be voting for this deal when it comes before the Commons tomorrow."
He said voting for the Withdrawal Agreement would support "siphoning us off from the rest of the UK" and argued it would mean businesses in Northern Ireland incurring "additional costs and administrative burdens".
Slamming Boris Johnson, he added: "We are disappointed he didn't stick to the red lines he said he would."
Foreign Secretary Dominic Raab today said the government had "certainly not given up" on their DUP "friends".
But he said "those that want to criticise or to block this deal will be holding Britain back".
He added: "It's not clear where they go and certainly not clear from listening to the EU that there will be any changes now."
Jeremy Corbyn was quick to dismiss the PM's agreement, criticising it for creating a customs border in the Irish sea, and saying: "As it stands we cannot support this deal."
A total of 635 votes will be in play when the deal is debated, which means the Government will need at least 318 votes to be certain of a majority.
If every Conservative MP who is able to vote also backs the deal, this gives the Government 285 votes.
Mr Johnson did not rule out suspending the whip from Tories who rebelled on Saturday, or say whether he would welcome back the 21 he exiled for previously voting against his will.
But he does have the backing of former Prime Minister David Cameron, who said he would back the deal if he were still an MP.
Speaking at Harrogate's Crown Hotel on the first night of the town's literature festival, Mr Cameron said: "I think it's much better to leave with a deal, and I think Boris has done well to achieve that deal. I hope he'll get it through parliament, I suspect he will but it will be tight."
