New figures from the Sainsbury's Bank Car Buying Index show that 5.4 million people intend to buy a car between February and July 2005, of which 1.11 million will take out a loan to help finance the purchase.

In total, it estimates that British consumers will spend £41.04 billion on cars in the period, at an average of £7,598 each.

These figures are slightly lower than those recorded in the period August to December 2004, where 5.34 million people purchased cars, spending £42.2 billion at an average of £7,900 each.

Rachel Brereton, loans manager at Sainsbury's Bank, attributed the fall to a market-wide slowdown in car sales.

She added that, in light of the fact that one fifth of sales are loan-assisted, she fears any interest rate rise could exacerbate this slowdown.

"We believe therefore that a rise in market interest rates could have had a significant impact on car sales," she concluded.