The final show of the series, which is known for giving sales boosts to artists who appear as well as the contestants themselves, featured Westlife, JLS, One Direction and Leona Lewis from Cowell's label as well as Coldplay (under EMI) and Michael Buble (under Warner Music).

"The X Factor final should feature the biggest acts in the world," said one senior industry insider. " Leona Lewis is already frankly on the way down. JLS and One Direction have already been ...