It seems that hailing a fuel-cell powered black cab won't be the only option for Londoners looking to grab a green fare. Now ready for trials, this plug-in electric conversion of the Mercedes Vito can carry up to six people and has a range of 120 kilometers on a single six hour charge.

The E-Vito taxi uses a 70kW, 300Nm Zytek electric drivetrain which slots into the engine bay with only minor modification to the engine mounts. It requires water, high voltage and low voltage connections tpo be added and talks to existing vehicle systems such as ABS, ESP and onboard diagnostics.

The E-Drive is married to a Vocis/Graziano transmission and the Vito has been converted to front wheel drive free-up space for the underfloor Li-Ion battery pack.

There's also a steerable rear axle which delivers a 25 ft (7.6 m) turning circle - something that's not only useful in London's poky streets, but also required by all licensed black cabs.

The partners in the programme are Zytek, Valence Technology, Penso and Mercedes-Benz UK, which donated the base vehicle.

Mercedes has recently rolled-out its own electric Vito - which it plans to begin delivering to fleet customers this year - in front of European ministers of economic affairs.