People have always called David Cameron a pragmatist, but the morning after the referendum he must have become a nihilist. Nothing else can explain the appointment of Oliver Letwin to lead the United Kingdom government’s Brexit unit. A prime minister who basically won an election by holding up Liam Byrne’s “I’m afraid there is no money” note has effectively dumped Oliver Letwin on to his successor’s desk – in all senses of that verb. I’m afraid there is no plan. I’m afraid there is Oliver Letwin.

Oliver Letwin! And come to that: unit! “Unit” implies a crack squad, an elite fighting force, a sort of A-Team meets Delta Force outfit whose moral grey areas are a trade-off with the extreme effectiveness best distilled in the famous Jack Nicholson speech in A Few Good Men. Deep down in places you don’t talk about at parties, you want that unit on the wall. You need that unit on the wall.

Instead, you’ve got Oliver Letwin. To fully absorb the fact Oliver Letwin is our guy at the sharp end of Brexit planning is to realise that even as the pound was nose-diving that first morning, we hadn’t reached rock bottom. There was a very deep concealed basement, into which we are only now beginning our journey.

Our tour guide is Oliver Letwin, a man whose chief claim to fame was once being the victim of one of those idiosyncratic Tory burglaries (see also Liam Fox). You know the sort of thing: when you let two strange men into your house at 5am in your pyjamas because they ask to use the loo, only to find – in a development that could only have been predicted by a computer the size of Los Alamos – that they nick your wallet. Or at least, that was Letwin’s chief claim to fame until last year’s declassification of a 1985 report he wrote for Margaret Thatcher in the wake of the Broadwater Farm riot, in which he suggested that social malaise was down to “bad moral attitudes” among black people, who would only re-route regeneration funding into the “disco and drug trade”. (He apologised when this came to light 30 years later.) …

… What’s the plan? “I’m trying to give you the truth,” Letwin twinkled terrifyingly, “which is that I have a completely open mind.” “Which is that you haven’t a clue.” Well of course he hasn’t. Oliver Letwin is your go-to guy if you want someone not to have a clue about something. In 2003, he pledged that a Tory government would automatically deport all asylum seekers to a foreign island “far, far away”. Where? He conceded he did not have “the slightest idea”. He is one remove beyond even Captain Hindsight, the South Park superhero whose speciality is showing up to disaster scenes and explaining what could have been done to avert them. Letwin is Captain I-Haven’t-the-Slightest-Idea. That’s the guy running the Brexit situation room.

“Why was there no mention of Brexit in the national security strategy?” wondered Blunt. “Because,” reasoned Letwin wholly unreasonably, “the government’s firm intent was to remain part of the EU.” And yet, for a government whose firm intent is not to be involved in a nuclear war, it sure has a lot of nuclear weapons. Perhaps it wishes to move to a situation where we wait to be hit by an intercontinental ballistic missile, then appoint Oliver to scratch around for some kind of plan for how to build a nuclear deterrent from the ashes. After all, the ever-upwardly-failing Letwin may be surely added to the list of things that would survive a nuclear holocaust.”