Simon Cowell feels "restless" with ITV while top executives at the broadcaster resent the TV mogul's huge influence over their network, biographer Tom Bower has claimed.
Writing in the Radio Times about his new book on Cowell, Bower said the 52-year-old is preparing for "aggressive negotiations" with ITV over the future of his shows.
His comments were published just days after it was reported that the X Factor and Britain's Got Talent boss was in secret negotiations with rival channel BBC One over a new drama.
Bower told the Radio Times: "Cowell remains restless, not least about senior ITV executives who resent his influence over the network and publicity about his louche lifestyle.
"With only one year to run on his ITV contract, he and ITV's chiefs are positioning themselves for aggressive negotiations over the network's most successful shows.
"Their respective strengths in their battle will depend on Britain's Got Talent's ratings... and whether Cowell successfully reinvents X Factor for the autumn series - or topples into decline."
Cowell, whose current series of Britain's Got Talent has been in a ratings fightback against BBC One show The Voice, was reported by the Daily Mirror to have told friends he feels "betrayed" by ITV.
The TV and music impresario is said to have felt that the broadcaster was "unsupportive" over Bower's biography, which revealed that he had a fling with Dannii Minogue.
He is also said to have been angered after ITV, which he has worked with for more than 10 years, poached a key executive from his independent production company.