Cheryl Fernandez-Versini has quit 'The X Factor'.

Cheryl Fernandez-Versini

Cheryl Fernandez-Versini

The former Girls Aloud singer has told Simon Cowell she won't be returning as a judge on the new season of the ITV show as she wants to focus on her solo career and her relationship with One Direction hunk Liam Payne.

A source told The Sun: "Cheryl told Simon of her decision at dinner last week in Los Angeles. They have had many discussions about the new series but she finally made up her mine.

"Her relationship with Simon is the best it's ever been and they both are incredibly supportive of each other

"Music is her number one passion and she has just started working on a new album which she wants out later this year.

"She's having a great time in the US with Liam and getting back to her pop roots."

However, Cheryl has told Simon that she is happy to offer advice if he needs it and he was understanding of her decision to walk away from the show.

The insider added: "Simon understands her reasons. He is supportive. 'X Factor' will always be a special show for her as it changed her life."

Cheryl is not the only judge to leave the show as DJ Nick Grimshaw announced earlier this year that he had quit after just one season.

And co-hosts Olly Murs and Caroline Flack have been replaced by Dermot O'Leary, who they ousted last year.

Louis Walsh and Sharon Osbourne have been tipped to return to the judging panel while Rita Ora's future on the programme has not yet been decided.