That said, there is one other person still in the running – Penny Mordaunt (of "she's not hiding under a desk" fame) – and she insists she's going to fight for the top job till the bitter end... Which is likely to be in just a few hours.
Struggling to keep up? Here's a handy breakdown of how things could pan out over the coming days, and how they probably will.
What will happen on Monday?
The parliamentary stage of the leadership contest will end at 2pm on Monday. This is the process by which candidates collect nominations from their 357 fellow Tory MPs.
Sunak and Mordaunt need the confirmed support of 100 colleagues to proceed to the ballot, but if only one of them gets 100 then they will automatically become the next leader.
The former (former) Chancellor has already secured more than 140 nominations but Mordaunt is still scrambling to scrape together even half of the required total (she’s currently on about 25).
The clock is ticking but, if she does manage to pull a rabbit out of the hat, the current Leader of the House of Commons will join Sunak for an “indicative” vote among MPs on Monday evening – this will be held between 6.30pm and 8.30pm, with the result announced at 9pm.
The hope is perhaps that the loser of the “indicative” vote may drop out of the race – because they’ve been named as the winner among MPs – in which case a new leader will emerge without the involvement of Tory party members (because we all remember how that went last time…).
In other words, even if they both get more than 100 backers, Mordaunt could still bow out after the indicative vote, so we could still have a new PM by the end of the day.
So what happens if the indicative vote does happen and no one drops out?
If Sunak and Mordaunt both get the backing of 100 MPs and neither of them drop out after the indicative vote, Tory members across the country who joined the party at least three months ago will take part in an online vote to decide the winner,
The ballot will close at 11am on October 28, with the result announced later that day.
Will there be any TV debates?
Tory Party Chairman Sir Jake Berry said Conservative HQ will be working with broadcasters to arrange one televised head-to-head so that members can hear from the final two candidates before they vote.
However, no hustings have been announced.
That’s probably because we already know who’s going to win…