The political guard is changing again

September's loser appears on the verge of becoming October's prime minister.

With the former Prime Minister Boris Johnson out, the firm favourite to be the new prime minister is Rishi Sunak.

Unless Penny Mordaunt assembles an army of supporters many times greater than those currently signed up, and between now and lunchtime, Mr Sunak's victory could be confirmed this afternoon.

Whatever happens there'll be a new prime minister by the end of the week.

Yes, a third prime minister in seven weeks.

An unprecedented level of turbulence; a calamitous series of events that most Conservatives acknowledge privately has amounted to a circus of absurdity deeply damaging to their party's reputation.

• 'Simply not the right time': Johnson statement in full

• How will the next prime minister be chosen?

It has been a weekend that had the ring of familiarity to it for those of us who've reported on events at Westminster for some time.

The question, not for the first time, was this: "What will Boris Johnson do next?"

Having flown back from the Caribbean, he spent Saturday and Sunday doing some attempted telephonic charming - working out how much, or little, support he had in the parliamentary party, just weeks after they got shot of him.

Consistently, from Saturday afternoon onwards, his team were briefing that they had the necessary numbers to make the ballot.

A cabinet minister, Jacob Rees-Mogg, said so publicly.

Another, Chris Heaton-Harris, went further, saying the necessary paperwork had been submitted to the party, including verified backers, that meant Mr Johnson could join the contest.

But the reaction to these claims was a reminder of one of the many issues a returning Boris Johnson would have faced - put simply, plenty, including on his own side, don't believe a word he says.

One of those very MPs did acknowledge to me privately, though, that things might have been very different if Mr Johnson had not been facing an inquiry into whether he misled the House of Commons during the lockdown parties rows.

Had he not been facing that investigation, the MP suggested, he might well be on his way back to No10.

But he isn't.

And he isn't because the numbers just didn't work. It seems, at best, he had persuaded less than a third of the parliamentary party to support him, which would have meant even a victory would have been pyrrhic and potentially disastrous - he knows what it's like to try to govern without the support of your parliamentary party. It doesn't end well.

And so, the political guard is changing again.

If it is Rishi Sunak, and there isn't a contest, I hear the King is in London on Monday evening.

If he's not in the capital before then, and Mr Sunak is confirmed as the winner this afternoon, perhaps he will wait until Tuesday to become prime minister so he can arrive in Downing Street in the light, during the day.

But let's see. Maybe just maybe, there'll still be a contest.

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• A very quick guide to Penny Mordaunt

What really matters, whoever the winner is, is they will inherit the same groaning basket of problems that proved too heavy for Liz Truss to bear: a deeply divided party, spiralling prices, grim public finances and a chorus of opposition parties saying they have no electoral legitimacy.

But they'll hope, too, the Conservative Party's apparent insatiable appetite for insurrection may finally be sated.

If it isn't, a toweringly difficult task will rapidly become impossible.