Motorists have been hit by "the most frustrating weekly rise" in petrol prices.
Government figures show the average cost of a litre of petrol rose by 0.7p in the past week to £1.31 at UK forecourts despite wholesale costs falling.
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Diesel rose by 1.1p per litre to £1.37, which is the highest level since March 2014.
It is the 15th consecutive week of diesel price rises, representing the longest streak in more than two years.
Petrol has gone up by 10% in the past seven months, while diesel has risen by 11% over the same period.
RAC fuel spokesman Simon Williams declared there is "no excuse" for supermarket fuel retailers to pass on the reduction in wholesale petrol costs.
He said: "This is the most frustrating weekly rise in petrol prices we have ever seen as there is no good reason for it.
"The wholesale price of unleaded has fallen dramatically since early October meaning the price of petrol should be coming down rather than still going up.
"We urge the big four supermarkets who are responsible for selling the largest quantities of fuel in the UK to cut their petrol prices now by at least 3p per litre to ease the burden on motorists and reflect the cost savings they are making."
He added: "The fact they haven't yet reduced the price of unleaded is sadly proof that rocket and feather pricing does exist. If the wholesale price had gone up as much as this they would definitely have passed it on at the pump."