Mayor Boris Johnson launched a 25,000-pound competition on Friday to design a new bus for London as part of his campaign to bring back the distinctive Routemaster vehicle.

Loved by tourists and locals alike, the distinctive red Routemaster double-decker buses were deemed expensive antiques and phased out in 2005 after half a century of service in the capital.

"I made a commitment during the election campaign to hold a competition to design a brand new bus for London, based on the much-missed Routemaster, which was an icon of the capital," said Johnson in a statement.

"London deserves a bus fit for the 21st century, and I want as many people as possible to submit their ideas.

"Whether you're a professional designer who can submit a detailed plan or you are someone who uses buses every day and has one great idea that would make your journey better, we want to hear from you."

Snub-nosed and light-bodied, with the driver enclosed in his cab and a conductor taking the fares, the Routemasters were built until 1968. At their peak 2,760 trundled throughout London but now only a handful are left on so-called "heritage" routes.

The open-door rear, which allowed passengers to hop on and off whenever they wanted was one of their strongest features - albeit one which health and safety officials frowned upon - while the use of the conductor meant that less time was spent at stops because tickets could be checked on the move.

Johnson will announce the winner of the 25,000 pound prize at the end of October. More details of the competition can be found on the TfL website at www.tfl.gov.uk/anewbusforlondon.