2010-03-22 09:27:02 -

MICHAEL BUBLE has given up alcohol to tour the world - because he fears h e won't be able to perform well enough if he's drunk.
The Canadian singer had previously vowed to dilute his alcoholic drinks while performing, after veteran

star Vic Damone berated the crooner for ruining his vocal chords with booze.
Buble confesses he is teetotal on his current global trek, as he wants to concentrate on putting on a good show for his fans.
He says, "I can't party on tour any more. I think it's part of getting older - you know your limits. I stay sober as I want to put on the best s how. It's bigger now, so I need to be sharp."