London's 300,000 daily black cab users will have a new taxi to ride in starting next year after Japanese carmaker Nissan unveiled its vision for the capital's black cab of the future.

Nissan says its vehicle -- based on its multi-purpose NV200 compact van -- is up to 50 percent more fuel efficient than London's existing black cabs, and cuts carbon dioxide emissions in half, in line with London Mayor Boris Johnson's plans to improve the capital's air quality.

Due to go on sale next year, the London version of NV200, which is essentially the same van-based vehicle announced last year as New York City's next taxi, is powered by a 1.5-litre diesel engine and seats up to five adults, Nissan said at the unveiling on Monday.

The engine could save the average London cab driver up to 1,000 pounds a year in fuel costs, according to the automaker.

Transport for London estimates there are about 22,000 black cabs on London's streets.

"From what I've seen of the NV200 London Taxi, it ticks all the right boxes. It's important that it looks like a cab, is comfortable with good ingress and egress and is reliable," said Steve McNamara, the general secretary of the Licensed Taxi Drivers' Association.

"If the fuel consumption figures are as promised, it will be a big seller."

The new vehicle will compete with the classic LTI taxi and a new Mercedes-Benz black cab.

Nissan, which expects the NV200 to receive full London Taxi certification later this year, said an all-electric version of the car would undergo trials in London next year.