One of Banksy's preliminary works for a mural is being raffled

Organiser Dominic Rowswell, 33, wanted to thank Bristol Children's Hospital after his 20-month-old son Loris was treated for asthma there.

"I got in touch with Banksy's agent and... he checked out what I'm doing and decided to donate a painting."

The piece is a preliminary work for one of Banksy's new murals on the West Bank barrier.

Draw date

Mr Rowswell, who also suffers from asthma, is running an exhibition featuring the work of more than 70 artists at the Old Bridewell Police Station in Bristol.

Some of the works on display are also prizes in the raffle.

"I wanted to see how much money I could raise on a zero budget," Mr Roswell said.

"I want people to know what amazing work the people in the respiratory ward do because without that my son wouldn't be here now."

"Another international artist, Nick Walker, donated one of his most recent Bristol landscapes entitled The Morning After.

"That sold minutes after being put in the gallery."

Raffle tickets are on sale for �5 at outlets via the Graffle website.

The draw for the winner will be made on 18 January 2008 at the Gorilla Gallery on Gloucester Road.