Sharp-tongued music judge can't hold a note

X Factor judge Simon Cowell has admitted he has a terrible voice.

The music mogul, who became a household name for criticising young hopefuls on reality TV shows, has turned down a cameo in comedy show Extras because he can’t hold a note.

Show creator Ricky Gervais had invited him on to sing an Elton John number during a karaoke event.

But Simon, 47, says: ‘I can’t sing. Why would I humiliate myself?’

Ricky, 45, reveals: ‘He said it was the one thing he couldn’t do. I wanted him to sing Daniel and he told me, “I can’t do it darling”. He said he’d do anything but that.’

An insider tells The Sun: ‘Simon’s singing voice is awful and there’s no way he would want anyone to hear it.’