It is likely to come on the forecourts within 18 months and the 4X4 vehicle is expected to be super-clean and put out less than 200g/km of C02 and return an amazing 40mpg. This will put it on a par with the latest 320 CDI.

No official statement is being issued, but a company senior source said, "It's a safe bet that our first move into hybrids will come with the M-Class using a 3.2 litre V6 Bluetec diesel."

By linking the 2-mode hybrid system, which has been developed with BMW and General Motors, Mercedes Benz believes it can outdo the Lexus trend-setting hybrid SUV, the RX400h.

The set-up uses an electric motor in the transmission to reduce weight, improve efficiency and absorb less power.

BMW's M5 is also likely to get green technology while the Chevrolet Captiva and the Opel Antara are the two General Motors vehicles which are also likely to get the new set-up.