Outside in Parliament Square, more than 500 protesters – including a handful of MPs – demonstrated against Labour’s reluctance to take antisemitism within the party seriously. Inside the Commons, Labour gave the impression of a party that had all but given up on itself. A party so at odds with itself and its leadership over many of the key issues that all that many of its MPs can do to express their support is to say nothing. The private grief of the opposition benches had never felt more passive aggressive.

Jeremy Corbyn was heard in near silence as he replied to the prime minister’s statement on last week’s European council meeting. Here was the Labour leader’s big chance to unite his MPs. To point out that Theresa May had just made the case for Britain remaining in the EU in her gratitude for the support she had received for her strong stance over Russia. To observe that almost all her Brexit red lines had long since turned green and yet still she was no nearer finding a solution to the Northern Ireland border. To make fun of her assertion that the British people were coming back together.

Instead, he seemed as if he was going through the motions. Distracted and lacklustre. More animated by the non-story of British passports than anything else. “Who will lead the negotiations?” he asked at one point. “Not you,” a Tory yelled. Normally such a boorish intervention would rouse the Labour benches to anger. Now, nothing. No one could be bothered to say a word in their leader’s defence.

As the session progressed, a few Labour MPs did rouse themselves. Yvette Cooper called out the prime minister for having no fallback position if a security treaty with the EU could not be reached. Chris Leslie admired the absurdity of having an implementation period in which there was no deal to implement. But it didn’t sound as if their hearts were really in it.

The prime minister was given a harder time by the Eurosceptics in her own party than she was by Labour. And even they were falling over themselves to give her the benefit of the doubt over her negotiating skills. On days like this, May might even begin to believe she has supernatural powers of survival.

While all this was going on, Corbyn kept his head down. More absorbed in the texts popping up on his mobile than in the proceedings. Hoping that his latest apology for antisemitism in the Labour party wouldn’t be seen as too little, too late. Moments later, the Labour leader had a chance to make partial amends. If not for the antisemitism – that would take actions, not words – then at least for being wrong-footed over Russia.

And at first it seemed as if he was going to take it. In a debate on Russia, he took a far tougher line than he had previously done. He accepted that British intelligence on the use of a Russian nerve agent in the attack on the Skripals had been accurate. He denounced the Russians for being less than open and said they had a clear case to answer. But when push came to shove, he couldn’t quite bring himself to point the finger at the Kremlin. There was still a chance some rogue agent had got hold of the novichok. The sound of clutching straws.

The few remaining Labour MPs in the house held their heads in despair. The Tories couldn’t believe their luck. Three times, Conservative MPs asked Corbyn to clarify if he believed the Russian state was behind the attacks and three times he declined. In desperation, Labour’s Ben Bradshaw stood up to say he had quite clearly heard Corbyn blame the Russian state. Corbyn thanked him for his intervention without confirming anything of the sort.

“I have been criticising Russia for 20 years,” Corbyn continued. This was too much for Labour’s John Woodcock who interrupted to say this just wasn’t true. This sounded close to an open declaration of war by the centrists. Enough was enough. Clowns to the left, jokers to the right and they were stuck in the middle with him. The Tories could only retire to count their blessings as Labour ate itself.