Record fuel prices have hit independent forecourt retailers the hardest with retail sales coming under pressure as more drivers opt to fuel up at the mults.

As the average price of a litre of fuel rose to a record high of 120p last week, retailers warned they were struggling to compete against big retailers, which could take a hit on margins.

"How can we compete against the supermarket up the road?" said one retailer. "We're a small business and need all the income we can get. We need people to come in and spend in our shop as well as buying fuel. With fuel so high, it's difficult to get them to do this."

Bill Ahearn, MD of Snax 24, said that its customers had been complaining about the price of fuel. "It is having an impact on other profit areas such as the shop but also the car wash," he said. "As for demand, our sales year-on-year are slightly up, but that is compared with the lows of last year."

Paul Delves, MD of Harry Tuffins, which has seven forecourt stores, added that although it was holding its own volume-wise, margins were tight. "We tend to go for a pence-per-litre margin," he explained. "So 3ppl on £1.19 a litre is less than 3ppl on 99p per litre."

Their warnings came as results filed at Companies House this week revealed sales at Park Garage Group had fallen 4% to £146.8m in the year to 30 June 2009, although profits had risen 16% to £444,000. The forecourt retailer is currently rebranding its store estate to its Park & Shop Life Essentials and Daily Essential fascias, as well as introducing 'pound zones' and promotions.

Retailers are also concerned that analysts are predicting fuel could top 150ppl in the summer. "If the pound recovers against the dollar the price may ease, but because the price is so loaded in duty and VAT, the effect will be negligible," said Delves.

The Forum of Private Business also warned that many small businesses were also being hit by soaring fuel prices. It has joined forces with The Fuelcard Company to help small businesses cut fuel costs.