BMW is expanding the number of eco-friendly vehicles in its line up with the introduction of plug-in hybrid models to the 2 and 3 Series ranges.

The new 2 Series PHEV will cost from £32,545 with the petrol-electric 3 Series priced from £33,395. The prices include the Government's £2,500 grant for plug-in hybrid vehicles.

Both will be arriving in April and will be followed later in the year with plug-in versions of the flagship 7 Series saloon.

BMW's first foray into plug-in hybrid technology arrived last year with the launch of the X5 xDrive40e which gave the SUV a theoretical fuel economy of 83.1mpg with emissions down to 78g/km.

In the new 225xe Active Tourer and the 330e the potential savings on fuel are even greater with the 3 Series rated at 148.7mpg (44g/km CO2) and the 2 Series achieving 141.2mpg with a CO2 figure of 46g/km.

The 225xe also gets the benefit of four-wheel-drive with the electric motor powering the rear wheels at speeds of up to 78mph and giving the car a 0 to 60 acceleration time of 6.7 seconds.

The 330e is powered by a 2.0-litre petrol engine delivering 184hp mated to an electric motor which gives an overall output of 252hp.

It can drive purely on battery power for up to 25 miles and has a top speed of 140mph with a 0 to 60 time of 6.1 seconds making it quicker than diesel alternatives.

Both models are fitted with multi-mode drive systems which enable them to be set up for a variety of conditions including conserving battery power for use in town traffic.

As well as increasing the number of plug-in hybrid models, BMW is also continuing to develop hydrogen-powered fuel cell vehicles and already has a prototype 5 Series Gran Turismo with a zero emission range of up to 300 miles.