Every new car in the UK will be required to display a new colour-coded "energy label" showing how much fuel the car uses and indicating its emission controls, according to new plans by the government.

The scheme will be unveiled this week by transport secretary Alistair Darling in an attempt to persuade car buyers to switch to more energy-efficient models.

"The labels will send a clear message to motorists that they can make a real difference by choosing clean, fuel-efficient cars," Mr Darling told the Independent.

The new labels are based on the successful A to G energy-labelling scheme already used on fridges, freezers and washing machines. Nearly all kitchen appliances now carry the top A or B ratings.

It is hoped that carmakers will start using energy labels to market their cars as a "consumer-friendly" technique.

What Car? magazine has reportedly agreed to promote the new scheme and it is hoped that others in the automotive industry will follow suit.

Tim Brown from the National Society for Clean Air and one of the scheme's architects, said: "Most big cars will have F labels, so the pressure will be on the car industry to move up the scale. People will have no excuse for buying gas-guzzlers."

Ministers are also expected to announce a new programme to give grants worth up to £1,000 to ultra-clean and ultra-fuel-efficient cars.

It is thought the scheme will begin in the autumn, with the labels potentially being linked to road tax bands based on a car's carbon dioxide emissions.