Controversial Labour figure Jackie Walker has been removed from her position as vice chairwoman of pro-Jeremy Corbyn campaign group Momentum after making controversial comments about anti-Semitism at a party training event.
Leaked footage showed the outspoken campaigner saying she had not found a definition of anti-Semitism she could "work with".
The footage also showed her questioning why Holocaust Memorial Day was not more wide-ranging to include other genocides.
Labour suspended her from the party last week over the comments.
Momentum's steering committee voted seven-three to remove Ms Walker from her position as vice chairwoman. The group said it does not regard her comments individually as anti-Semitic but raised concerns about her "irresponsible" behaviour.
Ms Walker remains a member of Momentum and its steering committee.
In a statement, the campaign group said: "Jackie's actions at Labour conference, in her subsequent Channel 4 interview, and by not understanding concern caused by her statements, have led the steering committee to view her behaviour as irresponsible and lose confidence in her as vice chair.
"Having read reports of what Jackie Walker is alleged to have said, listened to the leaked video, and heard Jackie's version of events, the committee does not regard any of the comments she appears to have made, taken individually, to be anti-Semitic.
"However, the committee does consider her remarks on Holocaust Memorial Day and on security of Jewish schools to be ill-informed, ill-judged and offensive.
"In such circumstances, the committee feels that Jackie should have done more to explain herself to mitigate the upset caused and should have been careful about statements on this and related subjects, whatever her record as an anti-racist, which the committee applauds."
Momentum said it was concerned that the leak "undermined much needed political education" and said she should not ultimately be expelled from the Labour Party.
Ms Walker, who is Jewish, previously released a statement apologising for any offence.
In an interview with Channel 4 News, she questioned why the Holocaust only marked genocides that happened after the Nazis.
When she was asked whether she had considered resigning given the outrage among some Jewish groups, Ms Walker said: "Some other prominent Jewish groups, of which I'm a member, think a very different thing.
"What we have to look at when we're talking about this subject, particularly at the moment, is the political differences that are underlying this as well."
Ms Walker said whoever leaked the footage from a Labour Party anti-Semitism training event "had malicious intent in their mind".
She also said she was anti-Zionist rather than anti-Semitic, adding: "I think Zionism is a political ideology, and like any political ideology, some people will be supportive and some people won't be supportive of it. That's a very different thing."