Oh the endless waves of smug. They rolled over the government benches. Did the prime minister agree that he had achieved a triumph? He did, he did. Could the prime minister confirm that the British people had broken free of the chains of subjugation that had been forged for them, link by link, in Brussels? He could, he could.

There was no truth in the idea that he had crumbs all the way down his front and there was no cake in sight

Parliament was debating Boris Johnson’s Brexit deal. The prime minister set the tone for the Conservatives, describing the deal as “one of the biggest free trade agreements in the world”. It was a triumph for Johnsonism. “We were told that we could not have our cake and eat it,” he said, before claiming to have achieved exactly that. There was no truth in the idea that he had crumbs all the way down his front and there was no cake in sight.

“British exporters will not face a sudden thicket of trade barriers,” he said, which will come as news to the government that he leads, which is running adverts everywhere telling British exporters to get ready for a sudden thicket of trade barriers. Several MPs rose to interject at this point, but sadly Johnson was too busy to take their points.

On he went. The deal protected fisheries, would give certainty to everyone, would protect jobs and investment. What about financial services, asked Labour’s Peter Kyle? “This deal does a great deal for services, for financial services, for the legal profession and many other professions,” Johnson replied, without a sideways glance at reality.

We could see a small cloud on the horizon. Theresa May was sat directly behind Johnson, wearing a black face mask, and making notes. But Johnson was oblivious, cheered on by his backbenchers.

He was especially smug about the fact that Labour was going to vote for the deal too. The party’s leader Keir Starmer made a decent fist of defending this position while attacking the deal. “There is only one choice today, which is to vote for implementing this deal or to vote for no deal, and those who vote no are voting for no deal,” he said. “Those voting no today want yes. They want others to save them from their own vote.”

It was true, and indeed the list of those voting against the deal included very few MPs who actually wanted a no-deal Brexit, but a lot who fancied a bit of low-cost political signalling. But of course it was true at the start of the month when Labour abstained on the government’s Covid tiers. Keir Starmer’s argument for not abstaining on the Brexit vote would equally have applied on Covid.

Starmer has, however, found a way of dealing with Johnson’s habit of just saying stuff. He took us back to Johnson’s claim last week that the deal eliminates non-tariff barriers to trade – or, as they’re known in plain English, queues and paperwork. “The prime minister knows that it is not true,” Starmer said. “Every member of this house knows it is not true. I will give way to the prime minister to correct the record.”

Johnson hesitated. Starmer urged him to speak. The prime minister cracked. “This is a zero tariff, zero quota deal,” he said, very much not denying that his previous statement had been untrue. “Typical deflection,” observed Starmer. He urged Johnson to stand again and make the position clear. This time, the prime minister demurred.

Johnson chuntered, but the angriest answer to Starmer came from May, who spoke next. “He said he wanted a better deal,” she fumed. “In early 2019, there was the opportunity of a better deal on the table, and he voted against it.”

Sir Bill Cash has been fighting to get Britain out of the EU since Bismarck was a lad

She was even ruder about Johnson’s deal, pointing out that the European Union had agreed to the tariff- and quota-free trade on her watch, not his. As for the rest of it, “we have a deal in trade that benefits the EU, but not a deal in services that would have benefited the UK”. It didn’t “excise the EU from our lives,” because it created “a whole structure of committees”. Nevertheless she would vote for it, as it turns out that a bad deal is better than no deal after all.

Did she have a point? Will the Tories who now praise the deal come back later in regret? Students of the prime minister’s past work will be aware that he is quite capable of cheering this deal today and denouncing it next year. That is, after all, precisely what he did with his last Brexit deal.

But hers was almost a lone voice of Tory pain. Speaking for most of them was Sir Bill Cash, who has been fighting to get Britain out of the EU since Bismarck was a lad. This was the most important moment since 1689, he said. “Our prime minister is, like his hero Pericles, the first citizen of his country and, like him, has saved our democracy,” he gushed. “Like Alexander the Great, Boris has cut the Gordian knot.”

Could he go on? He could. “Margaret Thatcher asked me what I felt about Europe. I replied, ‘Prime Minister, your task is more difficult than Churchill’s. He was faced with bombs and aircraft. You are faced with pieces of paper.’”

And so Britain’s EU membership closed with so many of the things that had dominated it: historical claims out of all proportion, a comparison to the Nazis, and a story that makes sense only to Bill Cash.