The Labour party is under growing pressure to reconsider its decision not to formally discipline one of Jeremy Corbyn’s allies after he accused Jewish “Trump fanatics” of making up allegations of antisemitism in the party.

Jewish community leaders reacted furiously to remarks made by Peter Willsman at a meeting of Labour’s national executive committee (NEC) earlier this month. The meeting resulted in the party refusing to fully adopt the International Holocaust Remembrance Alliance’s definition of antisemitism.

Willsman, an activist on the “JC9” Momentum-backed slate for re-election to the party’s ruling body, was taped saying he would “not be lectured” over antisemitism and accused some Jews “making up duff information without any evidence at all”.

Momentum activists also suggested Willsman should be removed from their leftwing slate, which would effectively destroy his chances of being voted back on to the NEC.

Marie van der Zyl, the president of the Board of Deputies of British Jews, said Willsman should be expelled from Labour and suggested that Corbyn, who was present for at least some of the meeting, should have intervened.

“Now Peter Willsman’s disgusting rant against the Jewish community and rabbis has been made public … he should be summarily expelled. Was Jennie Formby [the Labour party general secretary] there to hear what was said? If yes, why did she let Willsman off so lightly?

“Was Jeremy Corbyn there to hear Willsman? If so, what form did his professed ‘militant opposition’ to antisemitism take when he heard it? Why has it been so easy to clear Willsman after his slurs against the Jewish community, but anti-racist MPs Margaret Hodge and Ian Austin are still being put through the ringer?”

Two formal complaints were made about Willsman after the meeting but Formby said there would be no inquiry as he had apologised.

A Labour source said Formby had challenged Willsman during the meeting and told him that she had personally seen “sickening and disgusting” evidence of antisemitism within the party.

Hodge and Austin remain under investigation by Labour after they raised doubts about the party’s ability to tackle antisemitism.

In the recording of the NEC meeting, published on Monday by the Jewish Chronicle, Willsman is heard to say: “I think we should ask the … rabbis: where is your evidence of severe and widespread antisemitism in this party?” In apparent response to some other people raising their hands, he replied: “I’m amazed. I’ve certainly never seen any.”

Other pro-Corbyn figures have called for Willsman to resign. The singer Billy Bragg said: “You can’t deal with a problem if you don’t believe it exists. Pete Willsman has sat through a Labour disputes meeting at which the majority of cases pertained to antisemitism. How can he claim to have never seen evidence of it? He should stand down now.”

The former Corbyn aide Matt Zarb-Cousin tweeted: “Pete Willsman should withdraw from the left slate, which he shouldn’t have been anywhere near in the first place to be honest. You’ve had your time Pete, time to go. Let someone else have a chance, preferably someone who doesn’t downplay racism …”

Labour’s deputy leader, Tom Watson, also criticised Willsman. He tweeted: “For the avoidance of doubt: Peter Willsman is and always has been a loudmouthed bully. He disgusts me.”

The Labour MP Luciana Berger, the parliamentary chair of the Jewish Labour Movement (JLM), responded to the recording by calling for the party to suspend Willsman and conduct a formal investigation.

“Anyone listening to this recording will be appalled to hear the venom and fury directed by Mr Willsman at the British Jewish community,” she told the Jewish Chronicle. “That he accuses the Jewish community of falsifying social media and being ‘Trump fanatics’ in order to deny the serious concerns of 68 rabbis beggars belief.”

Cllr Joseph Ejiofor (@CllrEjiofor) Very few people who’ve never experienced racial discrimination can understand what it feels like to be the victim of racial discrimination. Jeremy is one. Willsman isn’t. PW won’t get my NEC vote; won’t endorse him nor encourage anybody else to do so He should be removed from JC9

Karen Pollock, chief executive of the Holocaust Educational Trust, said: “This tirade did not happen in some stuffy room of a fringe gathering in the back of beyond; this happened at a meeting of the ruling body of a mainstream political party with its leader present.

“It is horrifying – not only for its content, but by the fact that the Labour leader and general secretary sat by, witnessed these disgusting, indefensible comments and said nothing.

“It is impossible not to recognise Willsman’s contempt for the Jewish community, but even when it is staring him in the face, Corbyn seems unfazed. Our political leaders should be leading the charge against racism. To remain silent is complicit. This is unacceptable and terrifying.”

A Labour party spokesman said: “Labour takes all complaints extremely seriously. These are fully investigated in line with party rules and procedures.”

Last week, three leading Jewish newspapers in the UK published the same front-page editorial warning that a government led by Corbyn would pose “an existential threat to Jewish life” in Britain.

