Cowell calls Spears "sweet as a lemon" on "X Factor"

Judges from the reality series ''The X Factor'' (L-R) L.A. Reid, Britney Spears, Demi Lovato and Simon Cowell are pictured on a video screen via satellite from Miami, Florida, during a panel discussion at the Fox television network portion of the Television Critics Association Summer press tour in Beverly Hills, California July 23, 2012.

LOS ANGELES (Reuters) - Looks like Simon Cowell has a challenger on his hands in a competition for who can be the most nasty television judge.

Former pop princess Britney Spears is giving Cowell, the brutal British TV celebrity judge, a run for his money in her new job on the panel of U.S. talent show "The X Factor."

"You can't destroy that song, sweetie," "predictable," and "I want to know who let you on stage," were just some of the remarks delivered by the 30-year-old singer to contestants during auditions for the TV contest, according to early promotions for its second season that begins in September.

"Britney is quite mean, which I think you will discover," Cowell, who is both a judge and the creator of "X Factor", told TV reporters on Monday in a satellite appearance from Miami. In fact, he joked, she is "as sweet as a lemon."

Spears signed on to judge "X Factor" in May, making her one of the biggest celebrities on reality TV. The "Toxic" and "Baby One More Time" singer joined former Disney Channel star Demi Lovato, 19, on the panel after both Paula Abdul and Nicole Scherzinger were fired following a disappointing first season.

"They are harder to please than me or (fourth judge Antonio 'L.A.' Reid)," Cowell said of the two young pop singers. "They are very happy giving people a 'no.' They definitely have their own opinions."

Cowell, who made his name as an acerbic judge on "American Idol" said the pair were brought in to help lure younger viewers to "X Factor," which last year delivered only about half the viewers enjoyed by "Idol." Both shows air on the Fox network.

Spears said she was "just a very honest person" who was eager to help young singers on their way in the music business that has given her a 15-year career as one of the world's biggest pop stars.

"I have done eight tours and I have been in the music industry for a while, and I think being able to give back is really interesting," she said, explaining her decision to accept the job for a reported salary of $15 million.

Cowell said various changes were being made to the look of the show for the upcoming season in a bid to differentiate it from the plethora of other TV singing contests.

He also said he aimed to announce two new hosts in late August who he hoped would be a man and a woman without prior TV experience.

(Reporting By Jill Serjeant; Editing by Bob Tourtellotte and Cynthia Osterman)