Robbie Williams says his stage fright is like thinking you're going to throw yourself off a balcony.

The Morning Sun singer was amazed at how much his nerves spiralled out of control on his 2006 Close Encounters world tour and never knows how they will affect him.

He said: "I never know what I m gonna get until the day of the show itself. I did a tour and on that tour an awful lot of people came to see me, and I bit off a bit more than I could chew and I buckled.

"The stage fright went from being something necessary to prepare yourself for the big show to an overwhelming fear of, I can't go on, I can't go on. It's a bit like that feeling when you re standing on the balcony and you think you're going to throw yourself off. That kind of fear."

Robbie is still keeping tight-lipped about speculation he is to reunite with his former group Take That, despite reports revealing he joined his ex-bandmates - Gary Barlow, Howard Donald and Jason Orange - in the studio this week to record some tracks.

Robbie - whose best friend in the band Mark Owen missed the sessions as he battles to save his marriage to Emma Ferguson following his cheating confession - said: "I've got something very exciting planned for the end of the year, too. Separate to me, and that's very, very, very exciting."