Gordon Brown's economic growth revisions could spell new tax rises for businesses, analysts have warned.

After months of refusing to budge from his Budget forecast, the chancellor admitted on Saturday that world and domestic pressures have weighed on the British economy.

Brown said that a lethargic global economy due to surging oil prices and tightened consumer spending at home means that his predicted economic growth target of between 3% and 3.5% is unlikely to be met this year. Experts believe it is now more likely to be around 2.5%.

According to the Centre for Economics and Business Research (CEBR), Brown's over-optimism means he will either have to cut spending growth or raise taxes.

The group warned the levy could come in the form of a mix of stealth taxes equivalent to three pence on income tax.

Business leaders were quick to call for policy reform and decry the prospect of tax rises, while some complained Brown's forecast is still too high.

"The chancellor's new reported growth forecast still appears a little too high in our view," said David Frost, director general of the British Chambers of Commerce (BCC).

Frost said that it has predicted annual growth of 2%, and even in May when the economy was stronger, the group forecast growth of just 2.4%. He called on Brown to guarantee there will be no new taxes on business.

Blaming Brown for the slowdown is unfair, said Douglas McWilliams, chief executive of the CEBR, but the Treasury should have curbed its enthusiastic predictions when none of the 39 independent forecasters it monitors came close to the chancellor's forecast range.

McWilliams saved his criticism for the chancellor's handling of the announcement.

"[Brown] leaked the announcement that he was downgrading his forecasts to coincide with Hurricane Rita and on a Saturday when the financial markets were closed in the hope that he could get away with the minimum of adverse publicity," McWilliams said.

"And even now he refuses to accept responsibility for the forecasting failure, attempting to blame the world oil market.

"While it is certainly true that high oil prices are likely to mean a weak economy in 2006, the current year's consumer spending slowdown started just after Christmas and ought to have been staring the chancellor in the face when he made his forecasts for the March Budget."