Manufacturers are still not doing enough to reduce carbon emissions.

Average carbon dioxide performance in the car industry has only improved by 1.16% since 2006, according to www.cleangreencars.co.uk.

But Mini has bucked the trend, with its CO2 figure falling by 17.38%. It comes fourth in the top five manufacturers with the lowest CO² figure. Fiat takes the lead with 142.15g/km CO² followed by Peugeot, Daihatsu, Mini and Citroen.

The overall average of all cars sold in 2007 was 164.39 g/km CO² compared to 166.32g/km CO² in 2006. The original voluntary agreement was to reduce carbon emissions to 140g/km by 2008. Now, the aim is to reach 130g/km by 2012.