Robbie Williams is enjoying being an 'X Factor' judge more than anything else he's ever done in showbusiness.

Robbie Williams, Ayda Field, Louis Tomlinson, Simon Cowell

Robbie Williams, Ayda Field, Louis Tomlinson, Simon Cowell

The 'Angels' hitmaker believes he has been doing the "wrong job" for the last 25 years of his career, during which he has been a solo singer and in boy band Take That, because he's having the "best time" on the talent show.

He said: "The amazing thing is, since I started to do the show I can't believe I haven't done it before. I'm having the best time in showbusiness that I've ever had full stop.

"I've been doing the wrong job for 25 years!"

Robbie admitted he was "instantly" up for appearing on the programme as a panellist when his wife Ayda Field was offered a judging role.

He said: "Ayda got a call from Nigel, the producer of the show, and he said, 'Do you think Rob will do it if you do it, too?'

"Instantly, I was like, 'That makes complete sense, I'm totally in."

Robbie admitted the "success" of the show is partly down to him because he has mentored some of the most fruitful acts, such as One Direction and Olly Murs, as well as the likes of fan favourite Honey G.

He joked: "I'm not saying it's totally down to me, the success of 'X Factor' and the British music industry ... but it's close."

Louis Walsh has not returned as a judge for the current series, and show boss Simon Cowell admitted it was a "radical change" giving the Irish music mogul the boot.

When asked in a joint interview on 'Lorraine' if he is missing Walsh, Simon said: "Sometimes you've got to make a change, and a radical change.

"The best panel is one you'd like to have dinner with. And that's where we ended up."