It was hard to see what all the fuss had been about. The intellectual legend that is David Davis had always said securing a future trade arrangement with the EU would be the easiest deal in the history of David Davis Land. And in the end he was proved right. It was so easy that the government chose not to do anything about it for the best part of two and a half years and then cobbled something together at the last minute.

A day after her brief trip to Brussels, Theresa May came to the Commons to present the deal that she and Jean-Claude Juncker had scribbled down over 26 pages. What she had wasn’t a deal exactly – more a vague declaration that things might work out OK at some point over the next 15 years or more. Some things would happen if other unspecified things were also to happen. And if those things weren’t to happen, then some other unspecified things would happen as a result.

The prime minister paused, closed her eyes and took a deep breath. Willing herself to believe in what she was saying. Willing herself to be somewhere else. She opened her eyes. It was no good. She was still at the despatch box. So she ploughed on, her voice becoming ever more dissociated.

She was immensely grateful to Iain Duncan Smith and Owen Paterson for their fascinating and helpful suggestions on Northern Ireland. There was no need for them to worry about the withdrawal agreement because it probably wouldn’t be needed. But if it was, there would be no hard border because she had arranged for a first world war blimp to be positioned somewhere in Armagh. Along with an armed, quick-response badger taskforce.

The red lines on red mullet would remain in place. We would be protecting British fisheries by getting rid of the Common Fisheries Policy and replacing it with a Policy of Common Fisheries. Britain would be regaining the right to make its own laws providing that was OK with the European court of justice. Then for the coup de grâce. Chequers had been chucked. We wouldn’t be getting a Canada deal or a Norway deal. We wouldn’t be getting something in between. With luck an Iceland deal. But more likely, and to be more geographically accurate, one that was dead in the water.

This was one of Jeremy Corbyn’s easier outings in the Commons. A reply that even he couldn’t screw up. Fighting lack of clarity with lack of clarity was his specialism. All he had to do was not fall over, and criticise some bits for not delivering a hard enough Brexit and other bits for not delivering a soft enough Brexit. A little of something for everyone.

May desperately tried to convince the opposition benches that her deal that wasn’t a deal met Labour’s six tests, which only ended up in a humiliating shout of “Oh, no it isn’t”. Because what the occasion really demanded was for the Commons to degenerate into pantomime.

That, though, was the prime minister’s high point, as thereafter MPs from both sides of the house lined up to trash her draft agreement. IDS and Paterson made it clear she had wasted an hour of her time talking to them at Downing Street earlier in the week and that she would have been better off watching NCIS. Raab tried and failed to sound as if he wasn’t overwhelmed by his own self-importance, while Boris Johnson dismissed her statement for being “full of generalities and self-contradictions”. Perhaps Boris is more self-aware than any of us thought.

It was almost an hour before May got her first expression of support. And that was only from Damian Green, one of the few people who know her well enough to call her by her first name. Otherwise, it was back to the pile-on. Remainers accused her of betrayal and demanded a second referendum. Brexiters accused her of betrayal and demanded she go back and renegotiate the withdrawal agreement, the only thing that was legally binding and the EU was certain not to change.

Before long, the prime minister was in Maybot mode. “The backstop was the backstop because it was the backstop that delivered the backstop.” Complete nonsense. She knew it, everyone knew it, but she just couldn’t help herself. She was delivering on the deal that was delivering on something that was delivering on something else.

Not so much a political declaration as the martyrdom of St Theresa. The only thing she was delivering was her own head on a plate. In a way, the masochism was almost addictive; when Labour’s Helen Goodman inquired if the government was going to follow the procedure committee’s advice on a meaningful vote, May was defiant. Why go quietly? She was certain to lose the main vote, so why not lose another?