The UK’s ‘big four’ supermarkets have increased fuel prices every day since the end of March, increasing their average pump prices by more than 8ppl.

Supermarkets have increased the price of petrol and diesel every day since the end of March

Data from the RAC Fuel Watch shows that this is the longest run of consecutive daily supermarket price rises in the last 3.5 years and means that supermarket pump prices on 23 May averaged 124.74p for petrol and 127.69p for diesel, compared to 116.66p for unleaded and 119.35p for diesel on 26 March.

This compares to overall UK average fuel prices that have risen almost 8.5p a litre over the same period – although not every day. Petrol has gone from 119.78p to 128.29p and diesel has increased from 122.54p to 131.15p.

The rises are due to the price of oil increasing to above $80 a barrel, the result of the United States’ decision to re-impose economic sanctions on Iran, which is the third biggest oil producer in OPEC. However, the oil price has increased by $30 a barrel since last July as a result of OPEC (the Organisation of the Petroleum Exporting Countries) and Russia limiting production to reduce an oversupplied market.

Meanwhile the price of fuel is also being hit by a poor pound to dollar exchange rate of $1.33 which negatively affects the cost of fuel on the wholesale market as fuel is traded in dollars.

RAC fuel spokesman Simon Williams said: “The supermarkets are being very quick to pass on increases in the wholesale price of fuel brought about by a 17% rise in the price of oil to above $80. Sadly, RAC Fuel Watch data shows they are far faster at passing on rises in the wholesale price than they are falls.

“The outlook for fuel prices in the weeks ahead is not good with another penny a litre expected to be added to the current average prices of petrol and diesel. All we can do is hope the international forces which have caused the oil price to rise ease and take the heat out of prices on the forecourt.”