Simon Cowell teases Dermot O'Leary for not being rich enough.

Dermot - who presents UK TV talent show 'The X Factor', which Simon is a judge on - claims the music mogul taunted him when he overheard him discussing a car he was thinking of buying.

Dermot told Q magazine: "Me and some other people were chatting on 'The X Factor' set about a car I wanted to buy. It's an Audi but I was concerned about emissions. Simon overheard me, pulled a face, like my concerns were pathetic.

"He has two Rolls Royce cars and I don't think he's concerned about emissions, really."

Meanwhile, Ant and Dec - who host another of Simon's shows, 'Britain's Got Talent' - have also taken a swipe at the acid-tongued judge.

The pair - full names Anthony McPartlin and Declan Donnelly - have jokingly criticised Simon's timekeeping, insisting he finds it impossible to be on set when he should be.

Dec said: "The biggest pain is that he's always late. He can't be doing his hair or wondering what to wear so why's he so late?!"