Until the shock defection of Tory MP Dan Poulter to Labour, Rishi Sunak had enjoyed that rarest of things: a good week.
Over the past seven days, the prime minister has seen his flagship, long-delayed Safety of Rwanda Bill make it onto the statute books.
The bullish PM said that would see deportation flights to Africa finally get off the ground in the next 10 to 12 weeks and, ultimately, provide enough of a deterrent to “stop the boats” carrying migrants across the Channel from France.
Throw in a successful trip to Europe, during which he announced that the government will spend 2.5% of gross domestic product (GDP) on defence by 2030 and it’s easy to see why Sunak might be feeling pretty pleased with himself.
Poulter’s decision to cross the floor dramatically punctured Sunak’s bubble on Saturday night - and teed up yet another nightmare week for the embattled PM.
On Thursday, voters across England will go to the polls to elect around 2,600 councillors, as well as mayors in Manchester, Liverpool, Tees Valley, and the West and East Midlands.
Bar some possible exceptions, the results will not be pretty for the Conservatives.
The party is expected to lose anything up to 500 seats - around half the number they are defending.
Throw in the possibility that high-profile Tory mayors Ben Houchen and Andy Street could also fall and it is clear why officials at Conservative Central Headquarters are bracing themselves for catastrophe.
The extent of the Tory meltdown will go a long way to determining when the general election will take place - and even whether Sunak will still be leading the party when it comes around.
Conservative peer and polling expert Lord Hayward predicted “a bad night” for his party, in which they will lose at least 400 seats.
That is marginally more optimistic than Sky News pollsters Colin Rallings and Michael Thrasher, who say 500 Tory councillors are on course to lose their seats.
Either way, the results will pile yet more pressure on a prime minister who has failed to improve his party’s fortunes since becoming leader in October 2022.
Much will hinge on the fate of Houchen in Tees Valley and Street in the West Midlands. Both contests appear to be on a knife-edge.
Were they both to hang on, Sunak could at least point to some high-profile successes on an otherwise grim night.
But if they lose - and Labour insiders are sounding increasingly confident in Tees Valley - then there is a real possibility of Tory MPs entering a tailspin which could even see Sunak removed from office.
One Conservative aide told HuffPost UK: “If we lose those mayors then he’s in serious bother.”
Tory MPs need to submit 52 letters of no confidence to Sir Graham Brady, chair of the 1922 Committee of Conservative backbenchers, to trigger a ballot.
Party sources believe the anti-Sunak faction remain at least 20 short of the magic number, but a flurry could be sent in should next Thursday go particularly badly.
The continued uncertainty around the PM’s position has done nothing to dampen speculation that a summer election in on the cards, with wild rumours that one could be called as soon as Monday.
The logic behind such a move is that it would head off any attempts to unseat him in the wake of the local elections.
Intriguingly, Sunak refused once again this week to rule out going to the country in July - a date which which would meet his “working assumption” that the election will take place in the second half of the year.
One Tory adviser said: “Election preparations have really ramped up in No.10 in the last couple of weeks. They want submissions sent in for the manifesto so they can get it done as soon as possible.
“My hunch is that they want to at least give themselves the option of holding it at the start of July.”
But former Brexit secretary David Davis spoke for many of his colleagues this week when he said the government would be “off its head” to call an election now.
“It’s going to go distant, sometime in November, maybe even December to allow some of the economic improvements to come through,” he told Times Radio. “So no, it would be a suicidal thing to do in political terms.”
Whether it will be Sunak’s choice to make remains to be seen, however. Some Tory MPs envisage a scenario - albeit one which remains highly unlikely - in which he loses a confidence vote, a new leader is elected following an expedited contest and an election takes place in the summer or autumn.
Whatever happens, Sunak’s time in Downing Street is running out. He should enjoy the good days while he can, because there won’t be many more of them.