Britney Spears apparently "loves showing her powerful side".

The new judge on the X Factor US reportedly enjoys being straight-forward with contestants. Sources say the singer is proving she is back to her best by being authoritative and tough on the singing talent show.

"Britney has long felt underestimated and ridiculed by people in the industry," an insider told British magazine Closer. "She loves being able to show her powerful side."

The 30-year-old mother-of-two is reportedly raising concerns amongst the crew that her ''Queen of Mean" on air persona is spilling into her real life character. Show insiders have said that her fellow judge Demi Lovato has become the latest victim of Britney's sharp tongue.

"Demi's been making an effort with Britney, but sometimes she just blanks her," the insider continued. "When the live shows kick off she plans to be even more ruthless."