Passengers will get a "greener, light and airy" service when new double-decker buses, based on the old driver-and-conductor Routemasters, start running in London in 2012, it has been revealed.
The new buses will feature two doors as well as an open platform allowing passengers to hop on and off.
The final design of the buses, being made by Northern Ireland manufacturer Wrightbus, were shown off by London Mayor Boris Johnson.
The buses will be 15 per cent more fuel efficient than existing hybrid buses and 40 per cent more efficient than conventional diesel double-deckers.
The first prototype will be delivered late next year, with the new buses entering service from early 2012.
When he took office in 2008, Mr Johnson vowed to bring back a "greener" version of the Routemaster, which was first introduced in London in the mid-1950s.
The Routemaster was withdrawn from regular service in December 2005, although some still run on a limited basis on two tourist routes in London where they complement the full-time service.