This felt existential. As bad as it gets. The moment someone humane would call for a lethal injection. Not just the point when the Conservative party realised there was no coming back – but the time when Rishi Sunak knew the game was up. There was no fight. Just a bit of a passive-aggressive sulk. And that was only the Tory backbenchers. From the prime minister himself, just an incoherent jumble. Digging himself in ever deeper. There will be tears long before bedtime. It wasn’t meant to be this way. Rish! has been brought up to believe his entitlement is total. That anything he wants is within his grasp. All he has to do is get out of bed. And that’s not always essential. Even from under the Siberian goose down duvet, the world was his plaything. His brilliance is effortless. So when he set his sights on being prime minister it felt like an inevitability that he could bend the country to his will. That a grateful nation would kneel down before him. Yet for the first time he has encountered a spiteful reality. One that dances to its own tune. At first there was confusion. Followed quickly by denial. Now his psyche is disintegrating before our eyes. Inside a small man, there’s an even smaller toddler desperate for his mummy. Helpless. Mewling and puking. Rish! could have prepared for a couple of days for this prime minister’s questions. And still none of it would have made any difference. The King of the Road has run out of road. He just doesn’t have a good story to tell about anything. The country is visibly falling apart around him. At first it appeared only to be happening in slow motion. Now it’s on fast forward. The economy is tanking. The health service is falling apart. Immigration out of control. Sunak’s worst nightmare is bearing down on him in surround sound. And he’s not even asleep. Quite the reverse for Keir Starmer. All his ducks have lined up in a row, begging to be shot. Me, me, me. Getting closer and closer so that even he can’t miss. Generally if there’s a gag to be made, the Labour leader can find a way to mangle it. But for a magic 15 minutes or so, Starmer was blessed with the gift of the gab. The king of standup. The comedy gods were smiling. First up was a throwaway line about ancient relics. The Tory party! Boom! Boom! Then a seamless glide on to the immigration figures. Sunak could barely bring himself to stand up. Why bother, when he was just going to be knocked over time and time again. Immigration was too high, he mumbled. Though he wasn’t sure why or who was responsible. It was all a bit of a mystery. Leave it with him and he’d try to find someone qualified to answer. The marbles jokes couldn’t contain themselves. They started spilling out everywhere. Sunak had lost his! I know, I know. It’s still a bit rubbish. A bit obvious. But this is the Commons. Not the Hammersmith Apollo. Starmer gathered himself. How come Rish! had chosen to humiliate the Greek prime minister? What was it about an EU and Nato ally that he found so distasteful? Now Rishi just lost it. He was ready to declare war on Greece. Invade! Invade! Yesterday’s satire was turning out to be clear-sighted prophesy. He hates the Greek prime minister. The man was definitely a foreigner. That explained everything. And because he was a foreigner, he couldn’t be trusted. Kyriakos the Greek deserved to be deported to Rwanda. He had tried to talk about the Parthenon marbles, which were 100% British because we had stolen them. What a total shit! Beware Greeks bearing gifts … Scrub that. Beware Greeks. They were all as bad as each other. In tenser times, this might have sparked a full-blown diplomatic incident. But luckily, the Greeks understand that Sunak is only cosplaying the role of prime minister. The man really in charge of the country was Starmer. The man Mitsotakis had actually met three days earlier. The Labour leader gently explained that he had discussed immigration – ring any bells, Rish!? – before telling the Greek PM that he was going to hang on to the marbles but might be up for a loan arrangement. International relations 101. By now Sunak was a tiny puddle on the government frontbench. An unfortunate stain. He had no idea about anything. He had no idea that since Brexit, companies had been able to import foreign workers on 80% of the normal salary. He had no idea why he was even here. All he did know was that anyone who listened to Beethoven was a secret EU sympathiser. The only good music is English music. Can’t have any of that foreign rubbish. Really. This was our prime minister. One day we’ll all turn round and wonder if any of this actually happened. Starmer went for the kill. Rish! was in La-La Land. A parallel universe. A one-man war on reality. A small man with even smaller politics. Borrowing the old gag from John Smith, he was the man with the reverse Midas touch. Everything he touched turned to … Perhaps James Cleverly could finish the sentence. Jimmy Dimly became animated. He can’t resist a fight. But luckily for him the potty-mouthed homunculus who regularly takes control of Jimmy D’s brain was having a day off. “No one in Britain is listening,” wailed Sunak. It’s true. They weren’t. The person in charge of the microphones had switched off the prime minister’s so no one could hear him. The metaphors were having a car crash today. Everyone on the opposition benches burst out in spontaneous laughter. Not the canned variety you often get. This was the real thing. The Tories just sat. Inert. Shell-shocked. They shoot horses, don’t they? It got worse. It turned out everyone else, including the Conservative MPs, also wanted to have a go at him. Why was the government doing nothing about Islamophobia? Er … because it’s not that bothered about Muslims. What about the 40 new hospitals? They were definitely happening. In someone’s fantasies. Why did the OBR and the ONS think the economy was tanking? Because Jeremy Hunt was in charge of it. Where were all the immigrants? Fuck knows. The Home Office appears to have lost track of them all. Things can only get worse. Taxi for Sunak. But make sure it’s a British driver. Depraved New World by John Crace (Guardian Faber, £16.99). To support the Guardian and Observer, order your copy and save 18% at guardianbookshop.com. Delivery charges may apply. A year in Westminster: John Crace and Marina Hyde live in London and online On Monday 11 December 8pm-9.30pm GMT, join John Crace, Marina Hyde and Pippa Crerar for a livestream discussion on another year of anarchy in British politics. Book tickets here or at theguardian.live