Rocker Ozzy Osbourne has challenged sneering X-Factor judge Simon Cowell: “You get up and perform.”

The wildman of rock is furious that Cowell continually slags off kids who are churn through the TV show auditions in search of a showbiz break. Ozzy believes the show ‘damns’ people just for trying their best. “Tell you what, Simon: get up there and show us how it’s meant to be done,” he stormed in Heat magazine.

The 58-year-old rock legend says he would never join ...