A politician who thrives on drama and attention, Boris Johnson’s bombshell resignation on Friday night was true to form: once again the former prime minister left Westminster reeling, while also throwing in grenades against enemies that will ensure he remains in the spotlight for some time yet.

It was undoubtedly a shock: even one of his closest allies told me a few minutes after his excoriating resignation letter landed, that they had no idea this was coming. It was also vintage Johnson, as the former prime minister unleashed a full frontal attack on the protagonists he believed caused his demise: Prime Minister Rishi Sunak and the “kangaroo court” privileges committee who Mr Johnson insisted was always going to find him guilty regardless of the evidence.

As with his resignation from No 10, there was not a scrap of contrition or regard for the democratic process that had got him to this place (remember there was a Commons vote that kicked off the inquiry and there’s also a Tory majority on that committee).

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Instead there was fury, defiance and the threat of revenge laced through his remarks. He ended his statement saying he was “very sad to be leaving Parliament – at least for now”.

Cue frenzied speculation about whether he might find another seat to come back in before the next general election. Whatever he does now, what is clear is that he’ll be hurling in rocks from the sidelines at a prime minister he’s determined to destroy.

But surveying the scene of Mr Johnson’s bombshell the morning after, the timing of the detonation makes perfect sense.

We knew two things about the former prime minister: he was very focused on getting his resignation honours lists through, and he’d said himself at the privilege committee hearings that he wouldn’t accept the findings if members didn’t find in his favour.

Having received a copy of their report a few days ago, he’d clearly decided to quit rather than suffer the humiliation of being sanctioned and potentially suspended as an MP through a Commons vote. So when his honours list was secured and published, it was time for Mr Johnson to go.

We don’t yet know the findings of the committee – due to meet on Monday to decide whether to now expedite the publication of its report – but we do know from Mr Johnson’s furious response that it’s likely MPs determined he had wilfully or recklessly misled the House, and were preparing to recommend a suspension of more than 10 sitting days from the Commons.

We currently only have Mr Johnson’s versions of events, as the former prime minister looked to set the narrative on a report that is almost certainly going to be very damning indeed. We know the privileges committee has received more evidence regarding Mr Johnson, since the initial partygate hearings earlier this year.

Last month, Boris Johnson was referred to police over further potential lockdown breaches by the Cabinet Office, which had been reviewing documents as part of the COVID inquiry. His ministerial diary revealed visits by family and friends to the prime ministerial country retreat Chequers during the pandemic. The information handed to the police was also handed to the privileges committee as part of its investigation. While Mr Johnson’s spokesperson immediately dismissed claims of breaches as a “politically motivated stitch-up”, another figure told me that the evidence is damning and has Mr Johnson “bang to rights”.

“There was an expectation that MPs would try to avoid the highest sanction, that they have gone there means it must be pretty bad,” says one Whitehall figure, who believes that the privileges committee has been unanimous in its verdict against him (we won’t know that for sure until the report is out).

The big question on my mind now is whether Mr Johnson will – or can – stage a comeback, and to what extent he’ll be able to disrupt his political nemesis Mr Sunak from outside the tent.

When it comes to the former question, the former prime minister has clearly decided not to box himself in and there is a big chunk of the activist base, as well as the parliamentary base, that are Mr Johnson backers.

But it’s equally true that this close to an election, Conservative MPs don’t want to stoke division – with a nod to the old adage that divided parties don’t win elections.

His most loyal backers on Friday night rode out on Twitter and TV screens to denounce the privileges committee, rather than amplify further Mr Johnson’s pointed criticisms about Mr Sunak and his government.

For its part, the Number 10 team were relieved when Mr Johnson failed to lead a huge rebellion and don’t believe he had anything near the potency he once had. “We’re in a period where Rishi is doing well restoring trust after a period of distress,” is how one figure close to the PM put it to me. “I don’t think the mood in the party is pitch forks.”

That’s not to say Number 10 isn’t worried by an unleashed and furious Mr Johnson determined to settle scores, but, as another person put it: “He is one man, the party is more than that and we sometimes lose sight of that in the Johnson circus.”

But the criticisms Mr Johnson has levelled at Mr Sunak – justified or not – are potent. There’s the criticism of Mr Sunak’s handling of Brexit and failure to get a UK-US free trade deal, to his call for lower taxes and bemoaning the lack of political momentum going into an election.

Those in government might remark in exasperation that the relationship between Mr Johnson and President Biden meant a free trade deal is something he’d never had been able to do, but that doesn’t matter much – what matters is that these dog whistles rally a base in the party frustrated by the new regime. He already has in the new grassroots Conservative Democratic Organisation, a movement which he could lead.

What he’ll do next, we don’t know. But the signs are that he intends, with his allies, to be a political menace. A third by-election was triggered on Saturday after another key Johnson backer Nigel Adams announced he too was quitting Westminster with immediate effect. That on top of the two sparked by Mr Johnson and that of his closest political ally Nadine Dorries are the last thing his successor needs. Lose them, and it all feeds into the narrative that Mr Sunak is a busted flush.

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Boris Johnson stands down as MP with immediate effect
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There are obvious questions as to whether Mr Johnson will try to stand in Ms Dorries’ mid-Beds seat, where the Conservatives are defending a 24,000 majority, or return to another safe seat before the next election (there were plenty of rumours before all of this that Mr Johnson was on the look out for a safer seat than Uxbridge and South Ruislip).

He could equally return to writing a newspaper column or editorship. What’s clear from his resignation statement is that he still intends to hold the spotlight whether Mr Sunak likes it or not.

Those around him tell me Mr Johnson shouldn’t be written off and feels deeply aggrieved by what he sees as a campaign within No 10 and the cabinet office to defenestrate him, with briefings against him in the run-up to the publication of the privileges committee report and then vote in Commons. His camp believe fervently that Mr Sunak is trying to drive them from parliament and the party: they are defiant and this, if you like, is the beginning of a fight back. I’m told more resignations are likely.

For the current regime, Mr Johnson’s attack gives voice to those supporters angry that – in the words of one – Mr Sunak is unpicking the 2019 manifesto despite having neither a mandate from he public or party members. For many Conservatives, it is Mr Johnson who has the box office appeal and ability to connect with voters in a way that Mr Sunak does not. Those loyal to him are ready to rally should he mount an attempt to return to parliament.

There are detractors who say Mr Johnson is done, that the partygate scandal has damaged his standing with the public and the party beyond repair.

A snap poll out today by YouGov found that nearly three in four Britons believe Mr Johnson committed further breaches of COVID rules than those he’s already been investigated and fined for.

In some ways, the easier thing for Mr Johnson to do was make this resignation the concluding chapter of his political life. But instead he’s chosen to leave the door open to a sequel.

A politician who above all hates to lose, the question is, after all that’s passed, whether he still has the appetite – and ability – to try once more to win. Never rule him out.