Former En Vogue star Dawn Robinson has vowed to boycott an upcoming holiday Tv film about the R&B group, because the movie doesn't feature her character.

Bandmates Terry Ellis and Cindy Herron appear in En Vogue Christmas alongside more recent member Rhona Bennett, but Robinson, who quit the band for a third time in 2012, doesn't even get a mention - and so she insists she won't be watching when the movie premieres on U.S. network Lifetime on Saturday (22Nov14).

The singer tells Tmz.com, "I have no interest in watching it. It looks horrible. I'm sad for them (remaining members)... I'm extremely worried that this is going to be a trainwreck."

Tmz.com reports Robinson is even considering suing Lifetime bosses if they go ahead with plans to broadcast En Vogue Christmas this weekend, despite giving up all rights to the band when she first quit in 1997.

Lifetime chiefs have declined to comment on Robinson's attack.

The film centres on a young fan who inspires the Hold On hitmakers to reunite to save a concert venue.