In 2011, in the sitcom Outnumbered, the Brockmans have taken in a German exchange student, Ottfried. The Brockmans’ eldest son, Jake, asks Ottfried what English TV he likes.

Michael Portillo once told Johnson he would have to make a decision between politics and comedy. It is a tragedy that he didn’t take up comedy. With hints of Billy Bunter, Bertie Wooster, Jimmy Edwards, ‘Boris’ might have amounted to a passable, sub-Jack Whitehall confection. ‘Boris’ is his ursine, tousled, faux-bumbling self, whose goofs and gaffes somehow serve only to add to the affection in which he is held by the British public, despite the mortal danger of his incompetence.

For some, he was a living anachronism, a plummy old Etonian rolling around the public domain in search of a clue as to what he might do or where he might belong. For others, his very ineptitude as a politician was a bracing change from the dreary, scripted, pinstriped, managerial efficiency of New Labour. As a comedian, Boris, ‘Bozza’, ‘Bojo’, understood the value of self-deprecation. He also stood against seriousness. He understood how seriously anti-serious a significant majority of the British people were, how much they would forgo or forgive in the cheery, bullish name of anti-seriousness.

‘Boris’, even ‘Boris Johnson’, is not all that he is. His full name is Alexander Boris de Pfeffel Johnson. Boris is his outer, bluff carapace, a fatsuit. That is ‘Boris’. But driving him, like Davros inside the Dalek, is Alexander, his inner, demonic, ruthlessly ambitious, spiritually emaciated, compulsively amoral, truer self. Alexander is a perpetually famished, morally destructive creature driven by a lust not even primarily for power but for sex and for money. Alexander is an authoritarian, not because he desires to put in the effort of running a country but because his natural, ancient sense of entitlement is deeply ingrained. He has a ferociously short way with anyone who impedes his ascent.

I was at Oxford at the same time as Boris Johnson, two years above him. Coming from a state-school, lower-middle-class background, I was never more conscious of the class divide than when in closest proximity to those ‘highest’ in its order. They who went to Christ Church or Balliol (as Johnson did), rather than modest Hertford. They who joined the Bullingdon Club, or the even more debauched Piers Gaveston Society, or wafted briskly past you in Broad Street, their braying vowels trailing in the breeze like their college scarves. Those who descended from Eton or Harrow, took their gentlemen’s thirds and then, on graduating, took up the posts in the City awaiting them like an inheritance. The likes of them and the likes of me would never consort.

We went our separate low and high ways, Alexander, Boris and I. He turned his hand to journalism, baulking at humdrum detail which, like the blame, could be left to others. Despite his affable air, he was not clubbable – Alexander would never let Boris linger anywhere for long; he was always on the move, moving on. Boris was a badly dressed shambles, he smelt, his desk was a disgrace, his attention to deadlines scant. However, he had the knack of working up an instant whip of serviceable prose.

Sent to Brussels as part of the Telegraph’s bureau, Boris affected to speak terrible French, but Alexander was as fluent as Richelieu in the language. And he saw an opportunity, a money-making opportunity. He realised that most of his fellow journalists billeted in Brussels were pro-EU. Alexander saw an opening for extravagant, Eurosceptic, tub-thumping copy: the straight banana stuff. ‘People who complain that there’s no right-wing satire in this country should forget about what goes out on Radio 4 at 6.30 p.m. and remember that Johnson’s reports from Brussels for the Daily Telegraph in the 1990s were satires by any definition of the term,’ wrote Jonathan Coe. ‘And they set the tone and perspective for the British debate on Europe over the next two decades.’ None of this was born out of any convictions. ‘Convictions? I had one for dangerous driving but that was from years ago,’ Boris once quipped, with Marlovian insouciance. Bozza.

Boris Johnson first appears on Have I Got News for You in April 1998. He looks like a young relic, left high and dry by John Major’s honest efforts at meritocracy and the landslide of Tony Blair’s victory, which buried the Conservatives. Boris is a Conservative. Let’s have fun with Boris. And let’s cast a dark beam on Alexander.

Ian Hislop, on the opposing team, acts as prosecutor, as ever, with Paul Merton acting as a sort of defence counsel whose counter-argument for his client consists of shrugging his shoulders and saying, ‘I dunno, you got yourself into this mess.’ Hislop relates the case of a taped telephone conversation between Alexander and Darius Guppy, a friend and fraudster. Boris shifts uncomfortably. He first claims not to remember the incident, a flat-out whopper of the sort the comedy-loving British public sometimes warms to. He then describes Guppy as a ‘great chap’, though also, he admits, a ‘distinctive fraudster’ and a ‘major goof’. Hislop reminds him of their discussing beating up a journalist. ‘That did come up,’ says Boris, with admirably impeccable comic timing. In the laugh-ometer, that vital crucible in which the British test public figures, Boris has won himself a few more plus points. He recalls him and Guppy discussing mutual military heroes, including Rommel; he’s floundering in contradiction when Merton quips, ‘Hence Major Goof who you mentioned just now.’

Ah, the quip, the respite for Boris. Jonathan Coe, writing about this episode for the London Review of Books, pinpoints this as the moment when the show let Boris Johnson off the hook. In fairness, however, HIGNFY did prolong his discomfiture for a good few awkward moments. And there’s more to come, with chair Angus Deayton adding a word or two from the bench. Boris protests he has nothing to be ashamed of. ‘What are you not ashamed of?’ Deayton asks him. In an instant, Boris and Alexander go into a huddle and come up with the following formulation:

‘Whatever there is not to be ashamed of.’

The line goes down a storm. Boris goes on the counter-offensive, suggesting he’s been ‘led into an elephant trap’ and using a further excuse that the incident was ‘ten years ago’, as if morality has a statute of limitations.

A piqued Alexander wrote a piece claiming all the so-called ad-lib wit of HIGNFY was, in fact, scripted. Boris would later concede that this was another whopper, but it did not queer his pitch with the show. Hislop and Merton decided they liked Boris – not as a politician but as fodder for HIGNFY, a useful specimen of an extinct, risible strain of Conservatism, as unlikely to make a return in the twenty-first century as the straw boater. He is invited back. Paul Merton makes a running joke about Iain Duncan Smith, then leader of the Conservative Party, actually being a set of twins, Iain and Duncan Smith. What is this thing about Iain and Duncan Smith? Boris asks. Merton explains the joke.

‘Ah, I see, it’s a conceit,’ says Boris, as if humour were a curio to him. Boris is consciously capable of being very funny, knows about timing, knows the impact of a good line and exploiting his persona. His face is set in a permanent half-smile, an occasional, complacent smirk. But no one ever sees him laugh out loud from deep inside. That’s because Alexander, while fully understanding the use of humour, has no sense of humour at all.

In the same episode, Boris undergoes a Mastermind-type quiz from which he emerges with zero points. However, in this and his other appearances, through narrow eyes, scanning the room, inner machinery whirring, assessing the situation, Alexander knows he’s winning.

Following this appearance, he was high-fived in the streets by students, hailed by white-van men and let off for failing to buy a ticket by the train inspector because ‘You’re the Bozza off the telly.’

All this, however, represented a failure to take Alexander seriously. When Angus Deayton (unlike Boris Johnson) was dismissed from public life for unforgivable sexual peccadilloes, Boris was among those subsequently invited to guest-chair the show. Merton and Hislop put to him rumours that he might become leader of the Conservative Party. ‘Aidb,’ replies Johnson, one of those...