The bridge is run by an independent charity

If the application is successful, motorists will pay 50p to cross, up from 30p.

Tim Baines, clerk to the trustees, said the bridge is run by a charity and receives no money from government.

Anyone wishing to object to the rise should write to the Department of Transport by 2 December.

"Everything comes from the tolls and it is important to preserve the bridge for Bristolians, said Mr Baines.

"Imagine what would happen if we didn't maintain it? We would be left with a monument."

He added that motorists using pre-pay cards would pay considerably less than 50p a crossing.

About four million motorists cross the bridge a year.

The toll rose by 10p to 30p in 2003.