Labour has called on MP Chris Williamson to apologise for remarks suggesting that the party had "given too much ground" in its response to complaints of anti-Semitism.
A party spokesman said that the Derby North MP – a close ally of leader Jeremy Corbyn – should withdraw his "deeply offensive and inappropriate" remarks, which fell below the standards expected from MPs.
It is understood that general secretary Jennie Formby and chief whip Nick Brown are to meet to discuss what action should be taken against him.
Chris Williamson and over 90 members come together in unity to resist the next wave. Actual meeting starts at 1'30" in.
Posted by Momentum Sheffield on Sunday, February 24, 2019
Video footage showed Mr Williamson telling a meeting of the grassroots Momentum group that Labour's reaction to anti-Semitism allegations had been "too apologetic" and had led to the party being "demonised".
He had already provoked the party's ire by booking a room in Parliament for the screening of a film about an activist suspended for alleged anti-Semitism, something which a Labour spokesman described as "completely inappropriate".
The video, obtained by the Yorkshire Post, was recorded at a meeting in Sheffield in the wake of last week's resignation of eight Labour MPs to join the Independent Group.
It showed Mr Williamson receiving loud applause as he complained that the party had "given too much ground" to its critics.
He was also filmed saying he had celebrated the resignation of MP Joan Ryan, who quit Labour in protest over the handling of anti-Semitism and bullying complaints.
A Labour spokesman said: "These comments are deeply offensive and inappropriate and fall below the standards we expect of MPs.
"Downplaying the problem of anti-Semitism makes it harder for us to tackle it. Chris Williamson should apologise immediately and withdraw his remarks."
Responding to the video on Twitter, Jewish MP Luciana Berger – who also quit Labour for the Independent Group – said: "This is what I have left behind. It's toxic. Our country deserves so much better. #ChangePolitics".