It has been another pretty disastrous 24 hours for Theresa May.
Yesterday she was forced by Conservative MPs to say she would set out a timetable for her fast-approaching departure from Downing Street after the next Brexit vote due in the first week of June. (The same week as Donald Trump's state visit.)
Just as this was going on, Boris Johnson confirmed he would be standing in the race to replace her.
Then on Friday morning Jeremy Corbyn announced the collapse of talks between Labour and Number 10.
The two sides had been trying to see if they could find a way to break the impasse, but Corbyn said the instability of the government meant there was no point continuing.
So what happens next?
We can say with some certainty that May will hold another vote on the Withdrawal Agreement Bill in the week beginning June 3. True, she has broken promises like that before, but if she tried to cancel the vote again Tory MPs would change the party’s rules so she could be removed from office.
Before then it’s possible May could hold a series of indicative votes in Parliament to test whether any of the various Brexit options — from a second referendum, to her original deal, to Corbyn’s proposed customs union deal, to leaving with no deal — have a majority.
At the moment, it’s difficult to see MPs coming to any agreement on how to proceed, meaning May is likely to lose the June vote.
She will then have to explain how she intends to hand over power to a new prime minister.
There are at least 20 potential runners and riders: Boris Johnson, Dominic Raab, Jeremy Hunt, Sajid Javid, Michael Gove, Matt Hancock, Andrea Leadsom, Rory Stewart, Amber Rudd, Liz Truss, Esther McVey, Penny Mordaunt, Johnny Mercer, Mark Harper, Steve Baker, Graham Brady, James Cleverly, Kit Malthouse, Justine Greening, and Priti Patel.
The Tory party will want to hold the leadership contest as soon as possible and have a new prime minister in place by July.
The Tory party membership is likely to want a Brexit-supporting PM, which means Boris and Raab are the clear frontrunners. Remain-voting Tory MPs could attempt to prevent a Brexiteer from getting on the ballot paper, but that would be an extremely unpopular move.
That means that as things stand it’s odds-on that the UK will have a new Brexiteer PM by the end of the summer.
The new PM — whoever they are — will then have to either go back to Brussels to renegotiate the Brexit deal (good luck with that), or find a majority in Parliament for a way forward (seriously, good luck), by October 31. That’s the deadline for the extension of Article 50.
If no Brexit deal is agreed by then, the UK will have a choice between either leaving with no deal, revoking Article 50, or begging the EU to give us another extension.
The maths suggests that Parliament will vote to prevent a no-deal Brexit. You can bet a new Tory PM will not want to revoke Article 50, so in this scenario they would end up having to ask Brussels for a further extension.