Cheryl Cole's hopes of becoming a judge on the US edition of The X Factor are in crisis, according to reports.

Bosses are apparently fearful that the Girls Aloud star won't be able to attract an audience and are instead looking at established US names like Rihanna and Katy Perry.

But Simon Cowell is trying to persuade producers that Cole, who already judges the UK edition, is perfect for the role.

"Simon has been the only one pushing for her and trying to convince everyone that she'll be a big hit,” a source told The Sun.

"They want to see if the American public warm to her before she takes on such a high-profile role in one of the biggest shows on US TV."

The source added: "There have been lots of heated conversations and debates about it."

Rihanna has already been linked to the US edition of The X Factor, which is due to begin later this year.

(by Jason Gregory)