“I did not intentionally or recklessly mislead the House,” Boris Johnson writes at the start of his evidence to Parliament’s Privileges Committee. “I would never have dreamed of doing so.”

The result was a life horribly torn

There’s something heartfelt in that denial, as though the very suggestion of dishonesty pains him. You get this feeling again a little later when he discusses the suggestion that, addressing one of the Downing Street lockdown parties, he told those present that: “This is probably the most unsocially distanced gathering in the UK right now.”

“I do not remember saying the words,” Johnson writes, “and it seems unlikely.” Does it, though? Is it really that implausible that the former prime minister would have made an unwise off-the-cuff remark that later got him into trouble?

Unless, that is, we’re all missing something. Might there be another explanation for the distance between the sober, hard-working Downing Street that Johnson describes and the booze-fuelled chaos machine that has been depicted in photographs and insider accounts? Let me tell you about The Strange Case of PM Johnson and Mr Boris.

Johnson was an upstanding figure, a product of Eton and Oxford, a stalwart of the highly respectable Daily Telegraph newspaper, a man whose word was his bond, a Conservative MP, a faithful husband, a doting father. Unknown to his friends, however, he was conducting secret experiments in a laboratory in the basement of the Spectator’s offices.

There he developed a cocktail of chemicals that transformed him into “Boris”, a shambolic figure composed of all the lust and depravity so long suppressed by the upright Johnson. At first, Johnson drank his potion only to give himself the confidence to appear on episodes of Have I Got News For You? but as time went on, he realised he was no longer in control of when he turned from Johnson to Boris.

The result was a life horribly torn. Johnson would write a nuanced article about the challenges of integration in multicultural Britain, only to wake from a dream-like state and find that Boris had filed a column saying Muslim women resembled letterboxes. Johnson dreamed of evenings spent on the sofa watching re-runs of Cagney & Lacey. Boris, he dimly sensed, was fathering children all over town — Johnson lived in constant fear of being asked how many.

Seldom have I seen a case more horrifying and tragic than that of the noble PM Johnson and the hideous Mr Boris

At times he came close to being found out. In 2016, as Britain prepared to vote on leaving the European Union, Johnson had determined he would campaign for Remain and written a piece explaining his reasons. Preparing to email his piece over to the Telegraph, well ahead of deadline as ever, he felt himself transforming. When he regained consciousness four months later, he was appalled to find himself at a press conference celebrating Britain’s vote to leave. In the days that followed, he tried to piece together what he’d promised in that long bus ride of lies. Hoping that someone would intervene to save him from himself, he retrieved his original article and posted it to a journalist.

As Foreign Secretary, Johnson praised Theresa May’s Brexit deal. Three days later Boris denounced it and resigned. In the months that followed, Johnson voted for it. What was going on?

When he became prime minister, the problem only became worse. “Stay at home,” Johnson told the country. “Let the bodies pile high!” yelled Boris.

The statement to the Privileges Committee bears the mark of both men. “I wish, in retrospect, that we had given some thought to how these events could be perceived,” laments a distraught Johnson. “No one even sang ‘Happy Birthday’,” whines a peeved Boris. “This team was working together at all hours of the day and night: sometimes up to 18 hours per day,” explains Johnson, anxious to excuse his officials. “Many of these individuals wished me ill,” snarls a furious Boris.

It seems to have been Boris who attended most of the parties, and Johnson who is trying to work out what happened at them. To the Abba party, there is a single oblique reference. Neither Boris nor Johnson is coughing to that one.

The major plank of the statement is that, if the parties had been obviously illegal, someone would surely have pointed this out. For some reason, the staff being toasted by the prime minister were under the impression that someone senior thought that what they were doing was all right. As for the prime minister himself, Boris didn’t care about the rules, and Johnson can’t believe he would have broken them.

Johnson seems to suspect that staff in his press office may have been lying to him. Their flexible attitude to the truth may of course be why Boris hired them. With so many gaps in his memory, Johnson simply had to rely on their assurances that he hadn’t attended any parties, even if fragments of memory suggested otherwise.

It remains to be seen which of Boris and Johnson we will see giving evidence on Wednesday. Johnson thanks the Privileges Committee for their hard work? Boris complains that they’re moving the goalposts? Perhaps both will appear. I fear to guess which will occur. Seldom have I seen a case more horrifying and tragic than that of the noble PM Johnson and the hideous Mr Boris.