The iconic black taxi has been a given a "green" makeover with hydrogen fuel cell technology aimed at reducing air pollution in cities.
With many green powered vehicles attracting lower car insurance premiums, there could be a financial incentive for drivers as well as an environmental one once the "Fuel Cell Black Cab" is ready for the streets.
A prototype unveiled at London's City Hall demonstrated the new cab's efficiency and green credentials.
It is powered by a hydrogen fuel cell system and lithium polymer batteries and belches out only water vapour and no harmful gases. And it can run 250 miles on a full tank of hydrogen, which means no refuelling is likely to be required for a full day of operation.
London's deputy mayor for policing, and chair of the London Hydrogen Partnership, Kit Malthouse, said: "The black cab is a much-loved London icon, but it is also a significant source of pollution, especially in the centre of the city.
"This prototype Fuel Cell Black Cab, which emits only water from its tailpipe, is an exciting glimpse of how hydrogen technology could soon play a vital role in cleaning up air quality for urban dwellers."
Transport for London is set to operate five hydrogen fuel cell buses later this year, while London Mayor Boris Johnson is working with manufacturers to ensure all taxis operating in the capital have zero exhaust pipe emissions by 2020.
© Press Association 2010