George Galloway spoke about the Momentum row on his talkRADIO show, urging listeners not to be lured by the "discredited ultra-leftism" of those reportedly seeking to take over the group.
Our presenter also said Jeremy Corbyn is doing well as Labour leader, but the media aren't reporting it.
Last week Momentum's women's officer Laura Murray wrote a blog complaining that a group of rebels led by the Trotskyite Alliance for Workers' Liberty is trying to wrest control of the movement from Jon Lansman, who set up Momentum as a vehicle of support for Corbyn.
Galloway said he and Lansman have long-standing differences going back to their time as "foot soldiers" for Tony Benn, and he has little time for Lansman as a person or a political figure.
However, Galloway said "if you asked me to choose between Jon Lansman and the rag-bag of Trotskyite fragments who are trying to take over Momentum... then I'm with Lansman."
Turning to what he described as the "Alliance for so-called-workers'-so-called-Liberty", Galloway said they are "the vilest, the weirdest, the cultest, secretive gang of saboteurs, wreckers and provacteurs that I have ever known."
Our presenter also said Corbyn is besting Theresa May in the Commons every single week, his latest star showing coming today (December 14) when he grilled the Prime Minister on social care.
However, Galloway said, Corbyn's communications team have not yet been able to demonstrate this, and "saboteurs" within the party are distracting from his progress.
Listen to the interview above