The male team behind the 70s hit group Abba, Benny Andersson and Bjorn Ulvaeus, are rumoured to have agreed to appear on this years X Factor.

The pair, who also wrote hit musical ‘Chess’, are going to act as mentors to the competition finalists and Celebrity judges.

An X Factor source said yesterday: “This is a major coup for us. To get the guys who wrote Abba’s hits to be involved in our show is just amazing.�