American Idol is returning to a three judge format. The singing competition's 13th season will have a diminished panel for the first time in five years in a bid to combat the Fox show's declining ratings.

Kevin Reilly, Fox's entertainment chairman, also revealed current judges Mariah Carey, Keith Urban and Nicki Minaj had been invited back, despite veteran mentor Randy Jackson deciding to leave the panel. "The format will have fresh twists for next season," the TV boss said. Kevin went on to hint the expanded middle rounds were likely to be revamped since he believes they are responsible for dwindling viewing figures.

Speculation is rife as to whether first time judges Mariah and Nicki will want to return after a series of explosive public rows. The pop divas vicious spats - which saw Mariah up her security because she felt threatened by Nicki - have reportedly got so bad that Mariah is desperate to quit. "Nicki is really disrespecting her, and she's tired of trying to bite her tongue all the time. She's done with it all. She doesn't need the platform, and all the drama isn't healthy for her. She's also under fire with the producers for not being critical enough of the contestants," a source said.