London, Dec 13 : The duet between R&B singer Beyonce and Alex is no longer a sure item on the final of the X Factor show on December 13 night.

Beyonce, 27, was to perform her hit `Listen' in a duet with Alex, but her aides are yet to approve the deal, as they have no idea who Alex is.

"Simon is working hard to get Beyonce to take part. She is warming to the idea but until she's on stage he will not relax. It could go wrong any minute," the Mirror quoted a
source as saying.

"Alex is desperate to appear with Beyonce but doesn't want to get too excited in case it doesn't happen," the source added. (ANI)