Limmud: Labour antisemitism under Jeremy Corbyn has been 'exaggerated', says Jon Lansman

He also criticised Jewish anti-Zionists who argued complaints of antisemitism were manipulated by Zionists. They were “extremely unhelpful” not only to Labour-supporting Jews, he said, but to the Palestinians,” whose side they claim to be on”.

But there were audible splutters of incredulity when he contended the Chakrabarti report had made an “extremely good start” in tackling antisemitism within Labour ranks.

Sarah Sackman, vice-chairman of the Jewish Labour Movement, said she had been repeatedly asked at Limmud how she could remain in the party. Her response was that her left-wing beliefs and her Jewish values were “inseparable”.

She was loudly applauded by a section of the large audience after she said that JLM had campaigned for Sadiq Khan as Mayor of London “at a time when there were many communal bodies within the Jewish community that were calling for a distancing between Jewish people and the Labour party.

“But we saw in Sadiq someone who wanted to work with the community whose politics reflected our politics… and when I see the first liberal Muslim mayor of a global city anywhere in the world elected, putting into practice Labour values… and doing so as a conspicuous friend of the Jews, I am proud that we played our part in that.”

Jeremy Newmark, JLM chairman, urged Mr Corbyn to stand up and “take responsibility”.

He was applauded when he said, “You cannot support and profess to be friends of organisations like Hamas and Hizbollah, who contain statements urging and inciting genocidal antisemitism in their charter, and at the same time claim to be an anti-racist and opponent of antisemitism ,without that having an impact on the broader membership of your party.”

Lord Glasman, the academic and Labour peer, traced left-wing antisemitism historically in part to the ideas of Jewish Marxists who had seen it as their mission to liberate Jews from Judaism.

He also highlighted critiques of capitalism and colonialism where Jews always had “the face of the Rothschild family” and Israel was seen as an ally of the dominant powers. “The elders of the Protocols of Zion has become mainstream progressive thought – it is called class analysis,” he said.

He recalled recently visiting northern Nineveh in Iraq the day after its liberation from Daesh. “It was a terrible scene, holes in the ground full of dead women who were too old to be sold into slavery, there were crucified bodies on the walls, decapitated heads,” he said.

“That was bad but what was in a way just as disturbing was I couldn’t get anybody in Labour really interested in this. That led me to think why.”

In the same week as he returned, a Palestinian girl was shot at an Israeli checkpoint and he could sense the anger. Israel was regarded as a colonial force and hence“the cause”, while Hamas and Isis (Daesh) were seen as “the effect”.

Mr Lansman, who had earlier spoken at a panel on why Jews should support Mr Corbyn’s leadership, said he had enjoyed his first visit to Limmud. “I shall come again even if I don’t speak,” he said.