The £5 increase this year will generate an additional £11m for the Treasury, with total revenue from the tax expected to reach £128m from the 2.34 million car sales forecast this year.

SMMT chief executive Paul Everitt said that although the rise appeared nominal, he was concerned about further steps the Treasury could be tempted to take.

“We hope this is not a move by the Treasury to plug holes in its finances,” said Everitt.

“In the grand scheme an extra £11m in tax and a fiver for new car buyers might not sound like much. However, we fear that this every-little-helps approach could be the basis for further changes to motoring taxes in March's budget.”