To ask the Chancellor of the Exchequer what research has been (a) commissioned and (b) evaluated by his Department on the number of motorists who (i) cease using their car, (ii) reduce the number of times they use their car and (iii) maintain their driving levels following an increase in fuel duty; and if he will make a statement. (182680)

The Government are committed to achieving a sustainable economy. At Budget 2007, fuel duty rates were announced for the following three financial years, in order to provide certainty to business and consumers. It is estimated that these rates will result in a reduction of 250 million litres of fuel that would otherwise have been purchased by 2011-12, had duty been increased in line with inflation during the period.

This effect is driven by a number of factors—including more efficient driving, a reduction in the number of journeys taken, and an improvement in the efficiency of cars purchased. However, HM Revenue and Customs do not disaggregate these effects when calculating the overall impact of duty increases.