Labour must take "firm" disciplinary action against veteran MP Sir Gerald Kaufman following his allegations about "Jewish money" influencing Conservative policy, communal leaders have said.
Labour leader Jeremy Corbyn called Sir Gerald's remarks "unacceptable and deeply regrettable" on Tuesday, but no further action has been taken by the party.
Chief Whip Rosie Winterton met the 85-year-old Father of the House of Commons this week to discuss his claims that "Jewish money" had made the Tories more pro-Israel, and his allegation that Israel had "fabricated" terror attacks in order to execute Palestinians.
But the lack of formal disciplinary action or an apology from Sir Gerald prompted Jewish groups to push for a stronger response.
One senior figure in the fight against antisemitism said it was "poor" that Labour had taken six days to respond after Sir Gerald's comments emerged.
There would be significant disappointment if no additional rebuke was made, one communal source said.
The case was also compared to that of then Liberal Democrat MP David Ward, who had the party whip suspended after blaming "the Jews" for "inflicting atrocities on Palestinians" in 2013.
Labour's situation would be viewed dimly if its response to Sir Gerald was weaker than the Lib Dem action taken against Mr Ward, the figure said.
The Community Security Trust called for "firm disciplinary action". Jewish Leadership Council chief executive Simon Johnson said Mr Corbyn's response was a "welcome intervention", but said the group was waiting to hear whether Sir Gerald would apologise.
Board of Deputies president Jonathan Arkush said he hoped further "disciplinary measures" would be imposed.
Following Ms Winterton's meeting with Sir Gerald, Mr Corbyn expressed his "deep concern". He said: "Last week's reported comments by Sir Gerald Kaufman about the Jewish community, the Conservative Party and Israel are completely unacceptable and deeply regrettable.
"Such remarks are damaging to community relations, and also do nothing to benefit the Palestinian cause. I have always implacably opposed all forms of racism, antisemitism and Islamophobia and will continue to do so."
The party refused to comment on whether further action would be taken, and Sir Gerald has repeatedly declined to respond when approached about his remarks.
Sir Gerald's fellow Jewish MPs had led the condemnation of his remarks, made at a Palestine Return Centre event in Parliament last week.
He was recorded by blogger David Collier saying that the British government had become more pro-Israel in recent years.
The Board, JLC and CST had written to Ms Winterton and Mr Corbyn asking for action to be taken, and eight Labour MPs had sent their own letter calling for "formal disciplinary proceedings".
More than 1,500 people have signed a petition set up by grassroots group North West Friends of Israel that calls for Labour to take action.