Set to start first deliveries in early 2015, the model uses the underbody to house the lithium-ion battery, giving the same level of boot space as the conventional B-Class.

Tesla-developed technology delivers 177bhp and 251lb.ft of torque, with a claimed 0-62mph time of 7.9 seconds and a top speed of 99mph.
Merecedes says it’s the fastest accelerating five-seat electric car in its class as well as the most powerful and has the greatest theoretical range on a single charge.

Charging on a conventional home supply takes around nine hours. Using the fast charging cable supplied with the car reduces this to between three and four hours.

Mercedes is also offering an optional Energy Assist Package (£945). This uses a forward-facing radar to sense road conditions. When traffic is identified, increased recuperation is employed to make the most of any deceleration. Likewise, it can use signals from the COMAND system (when specified) to read the topography of the road ahead and adapt accordingly. The driver can override the regenerative cycle via the paddles mounted behind the steering wheel.

The package also includes a “Range Plus” button for occasional use, adding extra range to the battery capacity than would normally be feasible.

And to address safety concerns, the car will emit a subtle but audible signal at speeds of up to 18mph to warn pedestrians of the presence of the car.

Two trim levels are offered – Sport and Electric Art. Prices start at £31,950 for the Sport model. Subject to approval, an OLEV grant (£5,000) can be applied, bringing the on-the-road price to £26,950. The Electric Art is priced at £32,245 – reduced to £27,245 with the OLEV grant.