New labels which show how fuel-efficient a car is and its level of emissions are expected to have a significant influence on car buyers' choices, according to the latest research.

A massive 69 per cent of potential buyers would be influenced by the colour-coded scheme, according to a poll by online retailer jamjar for Auto Express magazine.

Of the 400 people surveyed, 276 said that the system would make them opt for a model with lower emissions.

The news was welcomed by environmental group Friends of the Earth. However it is calling on the government go even further by introducing four new road tax bands with £50 between each band.

VED for the most polluting cars should be raised to £500 per year within five years, they argue, with the cleanest, most fuel-efficient cars charged no VED at all.

Meanwhile there is scepticism in some quarters about the results of the poll. RAC Foundation's Edmund King said in a statement: "What interests people is running costs, not CO2 emissions."

"I am sure some will avoid the more polluting models when they see their fuel bill in black and white."

The initiative is expected to come in force in time for September's new registrations, which will result in cars displaying CO2 emissions information on their windscreens as well as information on fuel costs.

Although voluntary, dealers across the country have been showing their support for the scheme.