The Labour Party has suspended a member over anti-Semitic abuse only after a councillor accused the party on social media of failing to act.
Adam Langleben, who represents West Hendon on Barnet Council in north London, said he reported the woman to the party in July.
The member had shared anti-Semitic posts on social media, he said.
"The Labour Party is committed to challenging and campaigning against anti-Semitism," a spokesperson said.
Mr Langleben said the member, who lives in the Barnet constituency, had shared anti-Semitic posts via several social media profiles including on the @GazaBoatConvoy Twitter account.
He claims that despite the issue being raised with party officials, the member continued to attend party events and campaigns for months.
Mr Langleben said he hoped raising the issue would help "apply the necessary pressure for action to be taken".
Since posting his claims on Twitter, Mr Langleben said he had received anti-Semitic abuse.
"The response has been overwhelmingly positive. But clearly there's been a whole bunch of anti-Semitic filth thrown at me."
He added: "The Labour Party has had 100 years of fighting the anti-Semitic far right, but now needs to learn how to deal with anti-Semitism dressed up in the language of the left."
An official inquiry into anti-Semitism in Labour in June found an "occasionally toxic atmosphere".
The inquiry, by Labour peer Shami Chakrabarti, followed the suspension of MP Naz Shah and ex-London mayor Ken Livingstone amid anti-Semitism claims.