Launching in 2014, the S500 Plug-in Hybrid combines a 329bhp turbocharged V6 petrol engine and 107bhp electric motor, the latter being capable of driving the car for up to 18 miles on battery power alone, with its conventional powerplant decoupled.

The carmaker said it had benchmarked a figure of less than 75g/km to suit markets such as the UK, where the S-Class will now be able to avoid the London Congestion Charge. On the NEDC plug-in hybrid test cycle, the car was able to return 94.2mpg.

New features include a haptic touch accelerator pedal, with variable resistance to help drivers avoid switching on the petrol engine, and an intelligent energy management system which can assess gradients on the route ahead to maximise recuperation through the electric motor.

Mercedes-Benz has yet to announce pricing for its flagship model.