Naught’s had, all’s spent. Theresa May tried. She really tried. But she just couldn’t manage it. The toxic mix of Brexit and her own stubborn incompetence has corroded the prime minister from the inside, and now she’s little more than a fragile shell. Unable to do much more than mechanically go through the motions in pursuit of a vote that she knows to be unwinnable. Sartre would have killed to know such existential despair.

The Conservatives also recognise the game is up and that their leader’s authority is little more than an illusion. For May’s last-ditch effort to persuade the unpersuadable with a statement to the Commons, there were huge gaps on the government benches. Partly because few Tory MPs had anything to gain from putting themselves through such a numbing experience, but mostly to save themselves from having to witness a prime minister’s suffering. It was that painful to watch.

Glassy-eyed and shrunken, May retreated into her familiar safe place. A hurried, disengaged monotone. A phoned-in repetition of every other Brexit statement she had given over the past few months. She didn’t believe a word of what she was saying, but she was nothing if not dutiful. She had some letters from the EU. Letters that were elegantly written and contained no spelling mistakes, but sadly lacked anything legally binding on the Northern Ireland backstop.

After admitting that she had basically wasted the past five weeks by delaying the vote, the prime minister went on to make an unusual pitch. Remainer MPs should vote for her deal because if they didn’t then they would increase the likelihood of a no-deal Brexit, and leavers should vote for her deal because a failure to do so would increase the likelihood of no Brexit at all. Even a dodgy 1980s Amstrad computer would have detected that contradiction in its algorithms.

May left her greatest misjudgment to the end, by reminding MPs that history would judge them. This from a government that had mishandled the Brexit negotiations from the off, had awarded a ferry contract to a company with no ferries, whose defence secretary wants to paintball the Spanish and whose international trade secretary believes that a no-deal Brexit wouldn’t be as bad as Dunkirk. Great. At least we won’t be dive-bombed by Stukas on the beach. History certainly will judge this government and the verdict won’t be kind.

In a parallel universe, Jeremy Corbyn and Theresa May might have been an ideal match on a blind date. Both have a flair for the mediocre and instinctively misjudge the mood of the house. The Labour leader said all the right things in reply – the deal she was offering was exactly the same as the one the house would have rejected in December, etc – but he did so with little grace. This was a time for calm, measured, statesmanlike Jeremy. Not shouty, snarky Jeremy. For someone who is hoping to engineer a general election, he made little effort to engage those voters he needs to win over to become prime minister.

As so often, the two leaders set the tone for what followed. Even normally passionate speakers such as Ken Clarke, Anna Soubry and Ed Miliband sounded as if they were overwhelmed with the semi-detached ennui of déjà vu. Everything that needed to be said had been said months ago. Along with a lot that hadn’t needed to be said and had been said anyway. Step forward Owen Paterson, who yet again insisted that the Northern Ireland border could be solved by imaginary technology operated by badgers.

Several MPs from both sides of the house pressed May on whether she would extend article 50. Naturally, she prevaricated, because that’s what she always does. It’s her default mode. It’s one of the reasons the country is so screwed. Plaid Cymru’s Liz Saville-Roberts injected some edge into the debate by observing that May hadn’t been so insistent on respecting the will of the people when the Welsh voted in favour of having their own national assembly, but the moment quickly passed. The time for home truths was long over.

Then we were back to treading water. Monday was just a sideshow, with Tuesday’s vote the main event. Only then would we begin to see if the government did have a Plan B, or whether the only contingency was to repeat Plan A and hope for a different result. A plan that in the real world might be called the definition of insanity, but in the fantasy world of Westminster is increasingly viewed as a viable option. Brexit is making fools of everyone. Especially those who were already fools in the first place.