Simon Cowell was apparently angry that ITV bosses rehired Gary Barlow for The X Factor 2012 this year.
Simon, who previously claimed that Gary was "stiff" and "boring" during his first series last year, is said to have wanted another new judge on the panel.
According to new extracts in Tom Bower's unauthorised biography of the music mogul, Simon also mocked Gary's hopes of being knighted.
Simon also took swipes at Gary after he was awarded an OBE after organising the Queen’s Diamond Jubilee concert.
Writing in the biography Sweet Revenge, Tom Bower claims: “The announcement that Barlow would receive an OBE for arranging the event added to his irritation. ‘He chased that madly to get three initials after his name,’ he carped.”
The new chapter in the book also details how Simon was frustrated with ITV1 boss Peter Fincham for rehiring Gary, claiming that the Take That star was trying to take over from him!
“The ambitions of Barlow, he believed, were comical," the book says. "Ever since Barlow had clawed his way back after a disastrous attempt to become a solo star, Cowell was niggled by his conviction that Barlow was bidding to establish a rival entertainment empire and, like Paul McCartney, secure a knighthood.
“He enjoyed snubbing the man who foolishly asserted that he was the top judge, not Louis Walsh, by texting his criticism about Barlow to others.”