Labour MPs have criticised their colleague Chris Williamson for saying the party has been "too apologetic" over anti-Semitism.
In footage published by the Yorkshire Post, Mr Williamson, who is a close ally of Jeremy Corbyn, told activists Labour was being "demonised as a racist, bigoted party".
Deputy leader Tom Watson said he had been "deliberately inflammatory".
The BBC has approached Mr Williamson and the Labour Party for comment.
Labour has struggled to contain a long-running row over claims of anti-Semitism - hostility or prejudice directed against Jewish people - within its ranks.
Nine MPs quit the party last week, criticising the leadership's handling of the issue.
One of them, Luciana Berger tweeted in response to the Williamson video, saying: "This is what I have left behind. It's toxic. Our country deserves so much better."
WATCH: Chris Williamson tells a Sheffield Momentum meeting that Labour has been "too apologetic" about anti-Semitism... pic.twitter.com/zxtKdHQPvw— Liz Bates (@wizbates) February 26, 2019
At an event in Sheffield last week - organised by grassroots Corbyn-supporting campaign group Momentum - MP for Derby North Mr Williamson said: "The party that has done more to stand up to racism is now being demonised as a racist, bigoted party.
"I have got to say I think our party's response has been partly responsible for that because in my opinion… we have backed off far too much, we have given too much ground, we have been too apologetic."
Amid applause from the audience, he went on to say: "We've done more to address the scourge of anti-Semitism than any political party."
Momentum has not responded to the BBC's request for comment.
On Tuesday, Labour officials criticised Mr Williamson for booking a room in Parliament for a screening of a film about anti-Semitism and the activist Jackie Walker.
Ms Walker was suspended by Labour over allegedly anti-Semitic comments in 2016, and the documentary, Witch Hunt, looks at those and other allegations within the party.
A Labour spokesman said: "It's completely inappropriate to book a room for an event about an individual who is suspended from the party and subject to ongoing disciplinary procedures.
"This falls below the standards we expect of MPs."
Stephen Doughty, Labour MP for Cardiff South and Penarth, said Mr Williamson's comments in the video were "unacceptable" and had "no place in our party".
Mr Doughty added: "I have made clear to both the Leader's office and our whips that I expect urgent action to be taken."
Wes Streeting, Ilford North MP, commented on the Yorkshire Post's video too, saying: "Stomach-turning. No action will be taken."
And his colleague Stella Creasy, MP for Walthamstow, also expressed her unhappiness.
Yesterday Chris Williamson complained about a toxic culture in Labour. I told him about the toxic culture anti semitism created and why had to be expunged not ignored. Those who perpetuate it or minimise it bring the party into disrepute. No ifs, no buts. #standupspeakup— stellacreasy (@stellacreasy) February 26, 2019
Another, Neil Coyle, called on Momentum and the Labour Party to do something, saying "Actions speak louder than words."
Earlier this month, the Labour Party's general secretary, Jennie Formby, said the party had received 673 complaints in 10 months alleging acts of anti-Semitism by its members.