Gary Barlow is "surprised" Robbie Williams waited so long to become an 'X Factor' judge.

Gary Barlow and Robbie Williams

Gary Barlow and Robbie Williams

The 47-year-old singer - who was a panellist for two seasons - thought his former Take That co-star would have joined the show's judging panel of the show sooner, and he believes appearing alongside his wife Ayda Field was a "genius idea".

Speaking on 'Lorraine', he said: "I'm surprised he's waited so long to be honest.

"Rob's great telly, he just is. He's great to sit in a room with, he's just Rob. He's the centre of the room wherever he goes. I think it's a genius idea taking Ayda with him.

"I know what Rob's like, he doesn't really like new environments and I really think Ayda ... I remember the first time I met her.

"I remember coming home to the hotel and phoning everyone up and saying 'Rob's going to be alright, I've just met his fiancée, she's going to look after him, she's going to save his life.' "

The 'Angels' hitmaker recently confessed he is enjoying being a judge on the show more than anything else he's ever done in showbusiness, and believes he has been doing the "wrong job" for the last 25 years of his career.

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 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."