It's been claimed this week that show bosses are lining up an X Factor comeback from Sharon Osbourne to replace Tulisa on the panel next summer, with Sharon judging alongside Louis Walsh and Nicole Scherzinger.
According to The People, Tulisa now wants to get out of the show's "politics" and get back to working on her music, with a reunion planned with her group N-Dubz next year.
A source told the newspaper: "Tulisa is over it, she has had enough of the politics on the show and doesn't want to go back.
"She is getting worried about how she is perceived on the show and thinks it would be better to quit while she is ahead to carry on with her music."
X Factor's chief executive producer Richard Holloway confirmed this weekend that the next year's show would be getting a major revamp, including the judging line up.
He said: "There is not one element we will not be looking at carefully – from judges and start times to auditions and glitzy productions."
Speaking to the Guardian, he added: "It's our 10th anniversary in 2013, and we want it to be amazing.
"It's about who the judges will be next year. Do we reformat the show? Do we introduce a new element?"