X Factor bosses have reportedly banned Cheryl Cole from using Derek Hough as her sidekick at the Judges’ Houses stage of the competition. According to the Sunday Mirror, executive producer Richard Holloway vetoed the plan, meaning that will.i.am will join the Girls Aloud star to pick her finalists instead.

A source said: “Cheryl has barely spent a day apart from Derek and with his background in dance she thought he would be a great mentor. But when Richard Holloway got wind of the idea he stepped in and immediately said, ‘No’.

“This is the biggest show on TV so he feels that, likewise, mentors should be the biggest names in the music industry, not the judge’s latest squeeze. It’s unprofessional to say the least.

“Cheryl may adore Derek but unfortunately that feeling isn’t shared among the X Factor bigwigs. She was persistent in wanting Derek by her side, but it was explained to her that he is a dancer not a singer, and that The X Factor is about singing.”

The report also claims that Cole is worried about her role on the US version of The X Factor following Katy Perry’s stint as a guest judge on the UK show.

The insider added: “Cheryl felt Katy outshone her at auditions so it came as a double blow when she heard she was in the frame for X Factor US. It’s awkward for Simon because he doesn’t think Cheryl’s right for the US, but on the flip side he feels an obvious obligation to her.”