“I am getting on with the job!” It was magnificent, in a way. Vintage, undiluted Boris Johnson. Hair a mess, tie askew, shirt untucked, hand down his trousers, completely detached from reality. Like watching a blond dreadnought sinking beneath the waves, guns still blazing defiantly. A few of the crew still on board, having chosen, as it were, to go down with the shit.

It was the Twilight of the Boris, and we all knew it. In the hours before Prime Minister’s Questions, there had been resignation after resignation. It wasn’t the quantity of them, it was the names. There were people like John Glen, Robin Walker and Victoria Atkins, people who believe in playing for the team, finally at the ends of their tethers. But joining the calls for Johnson to just give it up were people like Lee Anderson and Jonathan Gullis, who had up to this point seemed, if not willing to take a bullet for the prime minister, certainly like they’d nut someone on his behalf.

No one could survive this, the total loss of support from both the dutiful and the bonkers, but the prime minister was determined that he would. We’d wondered if he’d even turn up for PMQs, but there he had been waiting to go in. Steve Baker was standing just over his right shoulder, well placed to plunge a knife into his back, if he could just find a spot that wasn’t taken.

After months of using hindsight as a taunt for Starmer, Johnson was now appealing to it

The backbenches were filled with people who had, until recently, been on the frontbenches. Keir Starmer had walked in to a cheer from his own side, and looked slightly surprised. In the gallery Charles Moore, the former Telegraph editor and a long-time Johnson-promoter, looked on, possibly wondering whether, with just one more set of really good advisers, the prime minister might be able to turn things around.

Starmer was, for once, brutally effective. He stuck to one subject, Johnson’s ever-changing story over Chris Pincher. Johnson on the other hand was all over the place. Yes, he had been aware of past incidents. “I greatly regret that he continued in office,” he said. Behind him Andrea Leadsom looked horrified at that. “In hindsight I should have realised that he would not change.” After months of using hindsight as a taunt for Starmer, Johnson was now appealing to it.

The Labour leader meanwhile was doing his best to taint the entire Conservative Party with Johnsonism. They had known who their leader was and defended him. Dumping him now was “the first recorded case of the sinking ship fleeing the rat.”

That got a proper laugh, and Johnson suddenly had the experience of what it’s like when the chamber is against you. He floundered. “He should hear what his lot say about him,” he eventually replied. It might have been more dignified if he’d just shouted “YOUR MUM” and run away. Instead, he stuck his hand deep down the back of his trousers, and pulled out the old stand-bys: defying the will of the people, Jeremy Corbyn, what about beergate?

These are lines that, in recent weeks, the Tory benches have treated like freshly minted quips from Oscar Wilde. Now they were met with Labour jeers. It was becoming painful to watch. In his final peroration, on how Labour was in the pay of the unions and, you know, Jeremy Corbyn, the opposition benches sat there waving at him.

The worst was to come from his own side: Gary Sambrook’s denunciation, Sajid Javid’s resignation statement. Neither was an example of great oratory, but each was devastating in its own way.

Sambrook revealed that, in private, the prime minister was undermining the stuff he said in public. Imagine. As for Javid’s speech, it was what political correspondents call “wide-ranging”, meaning it was a leadership bid. He offered himself as the anti-Boris: loyal to his wife and his party, a man who had worked for everything he’d got. He isn’t a great speaker, but if ever there was a moment for the Tories to decide they’ve had enough of the slick, this is surely it.

Johnson fled the chamber after that, to cheerful shouts of “Bye, Boris!” from Labour. I may not have seen them this happy in a decade.

But that was only the first course. A couple of hours, and a few more resignations later, we were back, for an appearance before the Liaison Committee of senior MPs. Sky News stuck a resignation counter in the corner of the screen so that we could watch the number tick up during his evidence. It may have been the best innovation in television since Roland Rat.

It was amazingly bonkers. He answered questions about the future of transport, and NATO, and defence spending, as though he was still going to be in the job next month. He began just admitting things. Sure, he’d met a former KGB agent without any officials present — “in Italy, as it happens”. What else were we going to get?

It was suddenly clear what was happening. This is what people mean when they talk about chickens coming home to roost. All the enemies Johnson has made, all the little slights, all the lies, they were all coming back at him in a single day. We just needed Jennifer Arcuri to drive a huge misleading bus through the wall to complete the set.

At one point he denounced people who thought that politicians were liars who were in it for themselves, saying they damaged politics. Boris Johnson, at that moment systematically trashing the reputation of every Conservative MP and every government official, said that. A man who had appointed a Cabinet so weak-willed that even after this they wouldn’t be able to persuade him to go. It was like a piece of performance art.

And he was loving it! Every time he was asked about his future, he told a joke. Of course he did. He was the centre of attention. The whole country watching him. Every tweet about him. This was the dream. Not all that tedious stuff about passing laws and deregulating markets. This was what he’d wanted all his life.

Bernard Jenkin demanded to know if he was going to call an election. “You’re asking about something that’s not going to happen unless everybody’s so crazy as to try and…” He trailed off.

“Unless what?” asked Jenkin, frantic. “Unless what?”

He didn’t answer. “I really don’t think anybody in this country wants politicians to be engaged in electioneering,” he said, making it sound like a threat.

It was glorious, bonkers, full-throated Johnsonism: crazy claims, total shamelessness, promises left, right and centre. He’s right. We knew who he was. This is what he was elected for. Respect his mandate.