The Federation of Small Businesses (FSB) is calling on the prime minister to fulfil a Conservative manifesto pledge to limit fuel duty increases.
Petrol prices are now at a record high after recent rises in VAT and duty.
The FSB wants David Cameron to introduce a fuel duty stabiliser which would cut duty when oil prices rise, and increase it when prices fall.
He backed the idea in opposition and said this week that he was considering ways to help cash-strapped motorists.
The FSB says the UK now has the second highest diesel price in Europe – something which it says is causing great difficulties for hauliers and other businesses dependent on road transport.
The organisation also points out that on the continent, the total price is split about 50/50 between the cost of the fuel itself and tax.
But in the UK, the average product price is 38% of the total, with the remaining 62% coming from tax.
John Walker, national chairman of the FSB, said they were “severely disappointed” with Mr Cameron.
“In opposition, the Conservative Party promised to put a fuel duty stabiliser in place – something the FSB has been calling for – but they have failed to deliver,” he said.
“We are looking at this because we do want to try and help people”
David Cameron Prime Minister
“As such, they are placing strain on already hard-hit businesses’s cash-flow. It is imperative the government acts now and introduces the stabiliser to avoid a relentless flow of fuel duty increases that simply put small firms on a knife-edge.”
The prime minister said last week that the VAT and duty hikes were “very painful and difficult” for motorists, adding that he was working with the Treasury on the idea of a stabiliser.
“We are looking at it. It’s not simple, it’s not an easy thing to put in place but I would like to try and find some way of, as I say, sharing the risk of higher fuel prices with the consumer,” the PM said.
“At the moment I think they feel they are bearing all of the burden so we are looking at this because we do want to try and help people.”
This article is from the BBC News website. © British Broadcasting Corporation, The BBC is not responsible for the content of external internet sites.