Robbie Williams, George Michael and Michael Buble will appear on the final of U.K. TV talent show "The X Factor" this weekend.

Each of them will duet with one of the three finalists on the final, which is likely to bring in huge ratings for ITV1. Last Sunday (Dec. 6) "The X Factor| averaged 12.7 million viewers, 46% of the total TV audience at that time.

"The X Factor" dominates the weekend schedules, with a two-hour edition on Saturday (Dec. 12) and the two-hour live final on Sunday (Dec. 13) at 7.30pm GMT.

On the final, Williams will sing with Olly Murs, Michael will perform with Joe McElderry and Stacey Solomon will duet with Michael Buble.

Judge Simon Cowell said the duets were a "very, very significant part of the competition." Last year's winner Alexandra Burke performed with Beyonce in the final.

The winner's song is expected to be a cover of Miley Cyrus's "The Climb" - she is tipped to perform on the show over the weekend, as she is in London for her first of five 17,000-capacity shows at the O2 Arena on Sunday.

The single will be available to buy as a download shortly after the final, and physically a few days later. Each of the finalists has already recorded a version of the winner's song, for release by Syco/Sony Music Entertainment.