Forced to summarise Theresa May’s Downing Street address to the nation last night, I’d go with: Prime Minister Kurtz … she mad. “They told me you had gone totally insane,” Martin Sheen says to Marlon Brando’s rogue colonel in Apocalypse Now, “that your methods were unsound.” “Are my methods unsound?” pants Colonel Kurtz. A pause. “I don’t see any method at all, sir.”

Or as one minister put it of May: “No fucking plan, nothing.” “One day there will be a public inquiry,” another member of the government observed, “and she will be judged to have been unfit for office.” Meanwhile, in the most ambitious crossover event since Avengers: Infinity War, the CBI and the TUC have put out a joint plea to Theresa May to return to at least the same postcode as her senses.

Alas, Emmanuel Macron is merely one of those believed to have had enough of le absolute bollocks

Instead, madam arrived in Brussels on Thursday afternoon, seeking just a short article 50 extension from EU leaders. Alas, Emmanuel Macron is merely one of those believed to have had enough of le absolute bollocks. The EU says it’ll only grant one if parliament passes her deal next week in Meaningful Vote 3: this time it’s meaningful. If May loses that, there are some suggestions that she is coming round to no deal, in a bid to keep her beloved Conservative party together. I realise you don’t care about spoilers at this stage, so let me confirm: that bid ends up failing anyway.

Still, back to the PM’s speech, which she really ought to have delivered in a yellow vest. If you’re keeping track of the various lunacies, please note that parliamentary sovereignty is no longer the glorious destination of Brexit but its evil enemy. It has long been a quirk of this uniquely artless prime minister that her sole memorable lines are ones that can only be said with sarcastic airquotes. “Brexit means Brexit.” “Strong and stable.” “Nothing has changed.” But Wednesday night’s scripted attempt to turn the people on parliament may turn out to be one for the history books. “I am on your side.” To which the only possible response, given her run of form, is: more’s the pity. May is the sort of player you want to sell to your bitterest rivals.

Yet her national address suggested that for all her well-established limitations, her thermonuclear dullness, and her mesmerisingly repressed inability to divulge even whether she mildly prefers Sherlock or Midsomer Murders, Theresa May is in fact an extremely dangerous individual whose priorities are now so far out of whack, she shouldn’t be anywhere near the controls of this particular automobile.

It was so ghastly that it contrived to unite entrenched enemies Mark Francois and Phillip Lee, who appeared this morning on Sky News. “You don’t persuade people by insulting them,” observed Francois, the ERG vice-chair. A little late for Mark to learn this lesson about negotiation, but he is merely a verruca on the footnote to this moment in history. Remain supporter Phillip Lee went further: “Whoever wrote the PM’s speech needs to have a long hard look at themselves.”

Play Video 3:52 Brexit: May says high time MPs vote for her deal in No 10 statement - video

Quite. It is not simply the prime minister behaving in this historically irresponsible way but her advisers too. The whole of the inner station is rotten. The only person who could have saluted it is aspiring memoirist David Cameron, who now has an excellent chance of being considered only the second worst prime minister since one or other of the great 18th-century inbreds (probably Lord North).

Not that you’d theoretically rule out both records being smashed by Jeremy Corbyn, whose Brexit strategy, even at the hour of peril, amounts to looking present but not involved. The Labour leader’s decision to leave a cross-party crisis meeting because Chuka Umunna was there confirmed him as a small and peevish man, who wouldn’t have what it takes if the chips were down. On an administrative note, though, anyone wanting to keep Corbyn in a meeting room next week should have an emotional support terrorist on standby to help him through the process.

Theresa May: don't blame me for Brexit crisis, blame MPs Read more

As for May, the received wisdom about her little lectern speeches is that they tell us nothing, but for my money this one told us everything. You could suddenly see it all, and at once. Back to mad Kurtz, in fact – though this time in the Joseph Conrad novel that inspired Apocalypse Now. “Oh, I wasn’t touched,” recalls Marlow, the narrator of Heart of Darkness. “I was fascinated. It was as though a veil had been rent. I saw on that ivory face the expression of sombre pride, of ruthless power, of craven terror – of an intense and hopeless despair.”

Mmm. Same. It was all there, from the contempt for parliamentary democracy to the mob-inciting tropes to her willingness to take terrible decisions out of self-interest or profoundly misguided factionalism. If May sees through what she implied, then all the hideously unwarranted insults thrown at others over the past two years – traitor, saboteur, enemy of the people – should legitimately be levelled at her.

As we head into the crunchiest of all crunch weeks, then, it must be said that only in a political class so bereft of heroes could people be hailing John Bercow as one. Bercow has been the subject of multiple accusations of bullying by people who have worked for him, and his apotheosis by some haute remainers is a reminder that Brexit has driven people on both sides crazy, or at the very least into behaviours of which they would, in their right mind, feel somewhat ashamed. I certainly don’t exclude myself from this analysis. After two and a half years of this shitshow, grasping at Bercow or an online petition or even no deal as the latest saviour is a form of rock bottom. We are all Renton from Trainspotting now, diving down the worst bog in Scotland in search of the suppository.

• Marina Hyde is a Guardian columnist