SPECULATION about a March 17 Budget clampdown on so-called 'gas guzzlers' appears to be doing little to worry those already running prestige cars with high fuel consumption rates. Large-engined prestige models would be first in the firing line if the Chancellor introduced steep increases in fuel duty, a Vehicle Excise Duty system graded according to engine size, or increased benefit-in-kind taxation for drivers of larger cars.

A BMW spokesman said 'reasonable' increases were unlikely to force, for example, 7-series drivers into smaller models. And Association of Car Fleet Operators director Stewart Whyte said companies whose senior executives ran large-engined cars would either accept the cost or, in some cases, ask them to downsize.

A spokesman for Mercedes-Benz said it would be unfair to penalise drivers simply for choosing a luxury car. 'We feel that someone buying an expensive car should not be penalised any more than someone buying a more modestly-priced car,' said a spokesman. Jaguar declined to comment.