Australia's Federal Chamber of Automotive Industries (FCAI) claims the new Labour federal government's planned increase in the rate of the luxury car tax had a significant impact on vehicle sales last month.

The increased tax hike was scheduled to take effect from 1 July and official sales figures for June showed an increase in the number of vehicles being sold in the affected market segments.

Sales of so-called 'luxury' vehicles were estimated to have increased by around 23%, or 1575 vehicles, last month, compared to June 2007.

"It is clear that many car buyers have brought forward their purchases in order to try to beat the proposed tax hike," FCAI chief executive Andrew McKellar said.

Despite the increase in sales for June, the automotive industry is concerned about the impact the ongoing uncertainty about the proposed tax increase will have on the market.

"With many people moving to get in ahead of the tax increase, we are likely to see a distortion in sales over coming months," McKellar said.

"It is another reason why the automotive industry appeals to the federal government to ensure that this proposed tax increase is not levied retrospectively," he added.

"People who have ordered vehicles before the senate has undertaken its inquiry into the proposed tax increase should not face the threat of being burdened with an additional tax bill, months down the track," McKellar said.