Supermarkets have increased the price of petrol and diesel every day since the end of March, adding more than 8p a litre to the average price at their pumps, analysis of RAC Fuel Watch reveals.
The outlook is not good for the rest of the half-term break, and possibly into the summer.
On 26 March a litre of unleaded bought at the big four supermarkets averaged 116.66p and diesel 119.35p – eight weeks later on 23 May their pump prices average at 124.74p for petrol and 127.69p for diesel.
UK average prices have suffered even more over the same period as a result, rising almost 8.5p a litre – 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**, combined with 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: “This is the worst series of consecutive daily supermarket price rises we have seen since we began monitoring this three and a half years ago.
“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.
“Supermarkets are highly influential in the price charged at pumps across the UK as, despite operating under 18% of all forecourts, they sell 45% of all fuel sold. While other fuel retailers don’t buy as frequently they will often match supermarket price rises which means they increase as the supermarkets do.
“Unfortunately, the higher oil price has come at a time when the pound has weakened considerably against the dollar. This causes pain at the pumps due to the fact that, similar to oil, fuel is traded in dollars so the lower the exchange rate, the worse the price gets for UK motorists.