The average price of petrol hit a new record of 191.53p a litre on Sunday, while diesel teeters on the edge of £2 a litre, coming in at an average of 199.03ppl.

However, this is slightly below the previous record high of 199.09ppl on 25 June.

But, many commentators are questioning why pump prices continue to rise.

RAC fuel spokesman, Simon Williams, said: “There doesn’t appear to be any sign that retailers are reducing their forecourt petrol prices despite average weekly wholesale costs having fallen for five straight weeks.

“The average cost of delivered unleaded was 145.7p a litre last week which after adding 7p a litre retailer margin and 20% VAT produces a price of 183p. Despite this, the big four supermarkets, which dominate fuel sales, are standing firm with a litre of petrol at their stores costing an average of 190.19p.

“We would love to hear their reasoning for keeping their prices so high in this instance, but we’ve never known them publicly defend themselves. Far too often it’s the smallest retailers, who sell far less fuel combined despite having more forecourts, that stand up for the industry.”

Williams added: “We’ve been lobbying the government for months to take further action to ease the financial burden caused by record pump prices. It’s time to take action and announce a further cut to duty or to VAT to help hard-pressed drivers and businesses.”

The government ordered a review of the fuel market amid price concerns, and the Competition and Markets Authority is expected to publish its findings this week.