Could it in fact have been a moment of far-sighted genius on the part of Boris Johnson, that with the television cameras pointed at him a fortnight ago, he spectacularly forgot the words police officers use when they arrest someone?

He’s been questioned at least eight times now on exactly why he prorogued parliament, and every single time he’s failed to mention the evidence on which he now finds himself relying in court.

It must be hard being Boris Johnson. When you are just as bad at lying as you are at telling the truth, how are you meant to know which you’re better off sticking to?

It is his weeks of lies about why he prorogued parliament that landed his government in the Supreme Court. And yet, now, somewhat awkwardly, he appears to have decided the way out of it is to start telling a variation on the actual truth. Rookie mistake.

Anyway, before we demean our basic dignity yet again, and concern ourselves with the details of today’s most recent phase of the never-ending turbo s***show that is the Johnson government, a tiny bit of background.

It’s August 28th. News breaks that Jacob Rees-Mogg has been to see the Queen at Balmoral and instructed her to prorogue parliament. This is immediately, and correctly, viewed as a move to stop parliament legislating to prevent no-deal Brexit, and thus the Queen has been lied to.

So the prime minister calls a TV camera and news reporter into Downing Street, and smirks his way through two full minutes of lies, about how this has all got nothing to do with Brexit. “We need a Queen’s Speech to get on with our exciting domestic agenda,” he lies.

His smirk, at that moment, seemed to be his way of acknowledging that he knew he was lying. That his “domestic agenda”, which would be part of this Queen’s Speech, stands absolutely no chance of getting anywhere because he doesn’t have a parliamentary majority.

Over the next few weeks, other Tories will be dispatched over the airwaves to maintain this lie. That this is all perfectly ordinary, that we need a new Queen’s Speech. It’s all fine.

It was important, back then, not to let slip that, as is crushingly obvious, the prorogation was for absolutely no other reason than to seek to frustrate parliament, and its attempts to legislate to prevent no-deal Brexit.

All of which, at least for someone biologically capable of feeling actual shame, and the prime minister is no such person, would potentially make it somewhat awkward, three weeks later, to instruct your lawyer to stand up in the Supreme Court, whilst watched by millions, and explain how proroguing parliament for explicitly political reasons is absolutely fine, and here’s all the times it’s been done before.

Lord Keen, with his horn-rimmed spectacles and detachable collared shirts, bears more than a passing resemblance to the fearsome, nameless “blue-haired lawyer” from The Simpsons, but his big day in court was a rather more Lionel Hutz-like experience.

In 1930, when Ramsay MacDonald prorogued parliament, he explained: “One might observe that it was clear that the executive wanted to avoid scrutiny because it didn’t command the confidence of the house.”

Then there was 1948, he carried on, when parliament was prorogued to force a bill to be passed. “This last example was clearly for a party political purpose,” he said. “It was a naked political reason.”

All of which is undoubtedly true. It’s just that your lad Boris Johnson, sitting a hundred yards away in his office in 10 Downing Street, keeps, keeps telling people he’s only done it for his “exciting domestic agenda”, his new police officers that keep fainting on him and publicly disowning him and so on – and here you are in court saying it’s all nakedly political, and that’s absolutely fine.

Still, Lord Keen wasn’t done here. We would also learn that prorogation was in fact parliament’s own fault. “If parliament did not want to be prorogued for longer than the specified period then it could and presumably would have said so,” he said.

Which is all very well. It’s just that some of us were there at 1am last week when a large number of members of that parliament tried to pin the speaker to his chair to stop him leaving, and started staging an actual rally in the chamber because, in your own words, Lord Keen, it very clearly did not want to be prorogued for longer than the specified period, and it could and indeed was saying so.

It was even writing so, on bits of paper, and waving them about while singing The Red Flag. It is fair to say that not many of the Supreme Court judges were impressed. Eyebrows were raised. Surprise was expressed. That is what counts as a savaging in these quarters.

By the time cases reach this, the very highest court of the land, they are beyond contesting or establishing the facts of what might have happened, and are matters of pure law.

At the start of the day the government was very much expected to win the case, and it may well be that has not changed. The reason for this is that, though the prorogation may have been something of a sharp practice, it was not for the courts to say it was or wasn’t illegal. That it isn’t “justiciable”.

“This court is not being asked to specify what would be a valid period of prorogation,” Lord Keen told them. That if prorogation had been extended for nakedly political intent, that’s fine and there’s nothing they can do about it.

Which, we will come to discover, may or may not be true. But in the meantime, there is also the court of public opinion to consider. And the question they have to ponder is this? Does it matter that the prime minister’s own defence in court is that he’s been lying through his teeth non-stop for three weeks?