Corbyn needed a moment in the TV debate that would change the campaign – he didn’t get one

The crucial thing is that it is unlikely many viewers will have changed their minds as a result of the clash between the Labour leader and the prime minister

Both candidates were most animated when they were most on the defensive during the leader’s debate. Boris Johnson did a good impression of being really quite cross about the suggestion that he would sell the NHS to the Americans. Jeremy Corbyn cut in on presenter Julie Etchingham’s question about antisemitism to launch into a passionate declamation about “the desperate history of the Jewish people in the 20th century”.

Neither will have persuaded anyone who thinks the worst of them. Nor did they get much by way of positive messages across. Johnson showed such message discipline in returning to “Get Brexit done” that he almost made a joke of it, and the audience groaned when he returned to it in his closing statement.

Corbyn’s positive message was more diffuse and possibly more effective. He tried to come across as a different kind of leader for different times. “My style of leadership is to listen to people,” he said.

He came across as more serious, more factual, and more in touch with the problems of real people – an affecting anecdote about the death of a friend who’d had to wait eight hours for treatment on the NHS stood in stark contrast to Johnson’s rhetoric. But Corbyn’s sanctimony sometimes grated, and some in the audience even booed him towards the end when he said it was the poorest in the world who suffered most from climate change.

I thought Corbyn came out of the debate better than Johnson, not by much – but it was like asking which was better, a documentary about poverty or Have I Got News For You?

The crucial thing is that I don’t think many viewers will have changed their minds as a result of it. Not least because it was too bitty, too rushed, too inconclusive. The stray things I remembered didn’t add up to a story. Johnson leapt at the chance to shake Corbyn’s hand – on a pledge to make politics politer, I think. Corbyn waved a prop: a piece of paper with every line blacked out to suggest that the government was engaged in a secret plot to sell off the NHS. But the opinion polls suggest the Conservatives are more trusted on the NHS than Labour.

Johnson had the only joke of the night when Etchingham asked him if he had found a money tree, and asked Corbyn if he had found two. “Money forest, he’s got,” said the prime minister.

Corbyn needed a big moment, and he didn’t get it. Johnson had his attack lines, and stuck to them. “Mr Corbyn” won’t say if he is for Leave or Remain. “Mr Corbyn” would give Nicola Sturgeon a referendum on Scottish independence as the price of power. “Mr Corbyn” has a “crackpot plan for a four-day week” that would bankrupt the NHS.

Corbyn had the whole of the last nine years of “austerity” before him and said it was all very bad, and most of the audience seemed to agree with him, but it didn’t amount to a call to arms. And it is Corbyn who needs to grab the attention of those undecided or persuadable voters out there and jog their elbow as they prepare to mark a cross by the Conservative candidate.

He didn’t do that in this debate. Nothing happened tonight that was big enough to shift the opinion polls, which suggest Johnson is heading for a majority in parliament. Corbyn might have just about won this debate but he is still losing the election.