Rock matriarch Sharon Osbourne has slammed Irish superstars U2 as "boring" and she finds their stage efforts especially pathetic.

The outspoken reality TV star has blasted the Irish rockers for treating their shows as a politically-laden news broadcast rather than a gig and insists they need to inject more energy into their performance.

Osbourne, whose husband Ozzy once bit the head off a bat on stage, says, "Talk about a knees-up? Have you seen U2's live show?

"It's boring as hell. It's like watching CNN."