Returning X Factor judge Cheryl Fernandez-Versini has likened Simon Cowell to an "annoying brother".

The pair will be reunited when the ITV series resumes on Saturday night.

Their friendship came to an abrupt end when Simon, 54, fired the singer from the US version of the show just weeks into her high-profile job in 2011.

Asked about the man she once described as her "frenemy" ahead of the new series, Cheryl, 31, said: " I think Simon's a bit like an annoying brother. We're like brother and sister and he's the annoying one.

"Simon has his very own way of being very annoying. He knows which buttons to push and he'll push them, and push them, and push them. But I play the long game. I'm waiting. Don't worry about me, I'll get my own back."

She said it had taken "a lot of begging and grovelling" from Simon to convince her to return to the show.

"It just felt like the right time to come back," she added. "I'd had enough time away to appreciate it and get really excited to find new talent again."

The judges - also including Louis Walsh and former Spice Girl Melanie Brown - have already begun filming auditions for the 11th series of the contest.

Cheryl said returning was "like riding a bike", adding: " The first time I did it I was terrified, but this time I was more excited."

She said she was worried about the addition of the six chair challenge, which was introduced last year and allows judges to swap acts in and out before settling on those they are taking to the judge's houses stage.

"I haven't yet, and I don't want to but unfortunately I'm going to have to, experience this chair business, where I have to switch people around in chairs which is making me feel physically ill at the thought!"

The former Girls Aloud star said she had "gelled really quickly" with Melanie but was less effusive about Louis, simply saying: "Louis is Louis."

Simon said he was happy to be back on the UK show.

"It actually feels really good to be back in the UK," he said. "I think in a weird way it's good I've had a break from the show, I've watched the show from a distance and now I feel like I'm back in control again. I like it."

He added that it "feels good" to be reunited with Cheryl.

"She's been on good form. It's almost like the last four years disappeared. We just picked it up straight away. She's been fun and annoying, but good to be with."

The age limit for the show has been lowered two years to 14.

Simon said: " You have to make a judgment call before you put teenagers in front of us, about whether they can cope with it or not. When they come to see us, we can make a pretty good call as to whether we think they're too young or too inexperienced."

Scary Spice Melanie, 39, described herself as a "really honest" judge.

She said: "I just call it how it is and whatever I see and whatever I feel, I just express that."

Asked how she thought the Spice Girls would have fared on the show, she said: " I'd like to think they would get through, but I don't know."

Louis, who is the only judge to have appeared in every series of the show, described this year's panel as "fantastic", adding: "This was meant to be. There's good chemistry between all of us.

"I think this year having Simon back is the most exciting thing. When he's around everyone is better. Everyone works harder."