Britney Spears' contract with The X Factor may not be renewed.

The 30-year-old popstar - who sits on the judging panel alongside Simon Cowell, Demi Lovato and LA Reid on the current series of the FOX reality show - is reportedly under threat because producers are eager to dramatically reduce the show's budget next season and feel they cannot justify paying her $15 million again in light of the show's disappointing ratings.

"Producers were hoping to pull in between 15-20 million viewers but the show hasn't reached those expectations and in a recent episode that clashed with the World Series only 5.7 million watched. Those numbers add up to cost cutting and Britney will be expendable. So, considering Fox has already renewed The X Factor for a third season, producers will be looking to spend less on the production of the show, including the judges' salaries. Britney, who was signed on a one-year deal, is the first person who will be expected to have her salary chopped. She is on a $15 million contract, which is absurd given that there's been no huge surge in the ratings," a source said.

But according to insiders the "Till The World Ends" singer is expecting an increase in her salary if she is asked to judge another series. "Problem is, when Britney signed that contract she expected to make more if an extension for a third season was agreed. That won't be the case now, and it is highly unlikely Britney will accept a pay decrease. It just doesn't make sense to spend all that money on Britney when Simon Cowell will undoubtedly be able to find another high-profile judge to replace her at a fraction of the cost," the source said.