Gary Barlow's first solo shows in over 11 years sold out within minutes of going on sale on Friday (28.10.11).
The Take That star is playing two concerts at London's Royal Albert Hall on December 5 and 6 - which will raise funds for youth charity The Prince's Trust and The Foundation of Prince William and Prince Harry - and Gary admits he's been stunned by the demand.
However, he has kept some seats back, which fans who missed out on can now bid for online, in order to maximise the money raised.
He said: "I've been overwhelmed at the response for both shows which sold out. Fans will be glad to know we've kept some back with great views of the stage to auction off to the highest bidder so we can make as much money as we possibly can for The Princes Trust."
The money made from the concerts will support the charity's City Riots Appeal, which is raising money for repairs and compensation for those affected by outbreaks and violence which swept the UK in August.
Gary added: "I'm glad the tickets have sold out so quickly - the money being raised is going to a cause close to my heart. The Prince's Trust's City Riots Appeal will help disadvantaged young people living in riot-torn areas."
Auctions of the remaining tickets will close at 8pm tomorrow (02.11.11), to bid visit www.gigsandtours.com/garybarlow