Jeremy Corbyn has been urged to ensure Labour backs tough new rules on anti-Semitism amid an "acutely embarrassing" row over comments made at the party's conference in Brighton which allegedly targeted Jews.
Labour members are debating new rules to clamp down on anti-Semitism which were proposed by the Jewish Labour Movement (JLM) and backed by Mr Corbyn and the party's ruling National Executive Committee (NEC), with a vote on the motion expected around lunchtime.
But it came as shadow cabinet member Jonathan Ashworth was forced to denounce "disgusting" allegedly anti-Semitic remarks reportedly made at a fringe event on Monday which prompted a backbench MP to accuse the party leadership of having an "ostrich" approach to the problem.
Mr Corbyn has previously faced criticism over his response to anti-Semitism, but Mr Ashworth said the Labour leader agreed with his calls to expel party members who make "pitiful" comments targeting Jews.
The Equality and Human Rights Commission urged the party leadership to take action.
Its chief executive, Rebecca Hilsenrath, said: "Anti-Semitism is racism and the Labour Party needs to do more to establish that it is not a racist party. A zero tolerance approach to anti-Semitism should mean just that.
"When senior party figures are saying there is a problem then the leadership should take swift action. It is not acceptable to simply say they oppose these views.
"These comments by party members show more needs to be done to root out anti-Semitic views that clearly exist in the party.
"Any suggestion of kicking people out of any political party on the grounds of race or religion should be condemned."
JLM chairman Jeremy Newmark said Mr Corbyn has to make sure the new rules on anti-Semitism are passed by the conference and put in place immediately.
Mr Newmark told Sky News: "Mr Corbyn must be acutely embarrassed by what should be a centrepiece celebratory conference after his achievements, the achievements of the party at the general election, (but it) has yet again been marred by headlines like this."
He went on: "He has an opportunity in front of him this morning with this constitutional amendment.
"He's backing it, John McDonnell's backing it, the entire NEC's backing it, but they need to show leadership and make sure conference delegates back it and implement it immediately afterwards."
The damaging row broke out after Israeli-American author Miko Peled told the fringe event, which was advertised in Labour's official conference programme: "This is about free speech, the freedom to criticise and to discuss every issue, whether it's the Holocaust: yes or no, Palestine, the liberation, the whole spectrum. There should be no limits on the discussion."
The Daily Mail reported he said: "It's about the limits of tolerance: we don't invite the Nazis and give them an hour to explain why they are right; we do not invite apartheid South Africa racists to explain why apartheid was good for the blacks, and in the same way we do not invite Zionists - it's a very similar kind of thing."
Mr Ashworth told ITV's Good Morning Britain: "We should have absolute zero tolerance when it comes to the quite disgusting and pitiful anti-Semitism that sadly we're sometimes seeing on social media these days, and indeed, as I believe if you look at the newspapers, I wasn't there ... was at an event in Brighton last night.
Asked whether the remarks gave those at the top of the party a lot of concern, he replied: "Yes, yes it has.
"And I think party members who make anti-Semitic remarks, who make some of these disgusting Holocaust denial statements, they shouldn't be in the party, they should be expelled."
Mr Ashworth said members were free to criticise the policies of the nation of Israel towards Palestinians.
"But that never justifies, never justifies anti-Semitism, never justifies Holocaust denial, and as I say, if there are people in the Labour Party making those comments at events then they should be expelled, if they are sending tweets along those lines they should be expelled, and I know that is the position of Jeremy Corbyn as well," he added on BBC Radio Five Live.