Alicia Keys, Leona Lewis, Take That, Girls Aloud and Leon Jackson lined up for X Factor appearances

The special guests and themes for some of the live X Factor shows have been revealed.

The guests invited this year include Alicia Keys, Take That, Girls Aloud and ex-X Factor winners Leon Jackson and Leona Lewis.

Alicia Keys will duet with White Stripes singer Jack White in Another Way To Die from Quantum Of Solace, the next Bond movie, in a James Bond themed week.

Leon Jackson is lined up to promote his single in the first live showdown.