Boris Johnson has won a Brexit deal from Brussels after 27 EU leaders agreed his alternative plan to deal with the Irish border.
But the real drama is to come on Saturday afternoon - when he has to convince enough MPs back home to vote it through.
That’s something Theresa May historically failed to do on three occasions.
So how do the numbers stack up - and what are the key figures who could swing it saying?
Here’s what we know.
How the numbers stack up - summary
After subtracting the MPs who don’t vote - chiefly Sinn Fein and the deputy speakers - Boris Johnson needs to convince 320 MPs to vote for his deal. If every MP votes, that is - if some abstain the figure to win will be less.
If every Conservative MP who is able to vote also backs the deal (clue: they won't), this gives the Government 287 votes, leaving a gap of around 30.
The most Theresa May ever managed was 279 - and she hadn’t just effectively sacked a bunch of her MPs for disloyalty.
There are 21 former Tory MPs who lost or quit the whip in order to oppose no deal. (The 22nd is Sam Gyimah but he's now a Lib Dem). Many of them will back the deal.
Plus there are a few Brexit-backing Labour and Independent MPs on the playing field.
But Foreign Secretary 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.
Apart from rebels, pretty much all the small parties - Labour, the SNP, Lib Dems, DUP, Independent Group, Plaid Cymru and Green Party - are set to vote against the deal. They have a total of 317 MPs.
Key groups to persuade
The DUP (10) - AGAINST
The DUP said their 10 MPs would not back the PM’s deal. And Brexit spokesman Sammy Wilson said they'll vote against it - not just abstain.
The Northern Irish Tory allies are furious at plans for a customs border down the Irish Sea, and the fact they won't get a veto on following EU rules in future.
Last-minute talks were continuing to try to win them round. But if Boris Johnson can't persuade them, he needs to find 10 further 'antis' to switch to 'pro'. A tall order.
On top of their 10 MPs, the DUP are also now trying to persuade Tory Brexiteers to stand with them and vote the deal down.
More of this below...
Brexit 'Spartans' (up to 30) - BOTH FOR AND AGAINST
The votes of the 20 to 30 hardest Tory Brexiteers are crucial.
Many were still undecided on Friday. Some were siding with the DUP - but others said Boris Johnson's deal was now the best chance of getting Brexit done.
Self-described 'Brexit hardman' Steve Baker said he would only announce which way the powerful European Research Group would whip on Saturday morning.
Former Tories (21) - MOSTLY FOR
There are 20 ex-Tory MPs who had the whip removed for blocking no-deal, and are still sitting as Independents. With Amber Rudd, who resigned, you’ve got 21.
Not all of these are hard-bitten retainers. A lot of them want a deal, and voted for Theresa May’s deal back in March.
Now Oliver Letwin, one of their number, has suggested as many as 17 or 18 will back the Brexit deal. Winston Churchill's grandson Sir Nicholas Soames is among Tory MPs who voiced their support.
Plus you’ve got Charlie Elphicke, who is currently sitting as an Independent after having the Conservative whip removed. He was likely to back a deal.
Labour backbenchers (approx 12) - FOR
Without enough support from his own benches, Boris Johnson must look to Labour.
It's thought up to about a dozen Labour backbenchers could support a deal - some of them full-blown Brexiteers, others from Leave-voting seats who don't like Brexit but believe the nation needs to move on.
The Brexiteers include Kate Hoey and Kevin Barron, both of whom have said they are standing down at the next general election .
Others may abstain, lowering the threshold for a Government victory.
Labour is trying to keep the number of supporters as high as possible by talking to wavering MPs and persuading them not to back Boris Johnson.
The party warned of "consequences" which could include losing the whip.
Other Independents (14) - MANY FOR, BUT NOT ALL
There are other Independent MPs - some of them suspended from their parties, some of them quit, some of them without a political home.
Many backed a deal last time including former Lib Dem Stephen Lloyd and former Labour MPs Ian Austin and Frank Field. Their number also include former Tory Charlie Elphicke who is a Brexiteer.
But the Independents also include Dame Louise Ellman, who has just quit the Labour Party but is unlikely to back Boris Johnson.
