Fuel retailers have been accused of ignoring chances to stop hiking petrol prices at the pump.
The RAC claimed significant reductions in wholesale costs for petrol mean companies have a “clear opportunity” to stop raising pump prices.
Data firm Experian said the average price of a litre of petrol at UK forecourts reached a new high of 191.1p on Sunday.
Diesel prices reached a record of 199.1p per litre on Saturday, before dropping slightly to 198.9p per litre a day later.
The Competition and Markets Authority launched a “short and focused review” of fuel prices earlier this month after a request by Business Secretary Kwasi Kwarteng.
The concept of rocket and feather pricing for fuel involves retailers quickly hiking pump prices when the cost of oil rises, but being slow to pass on the benefits of decreases in oil prices.
RAC fuel spokesman Simon Williams said: “We are struggling to see how retailers can justify continuing to put up their unleaded prices as the wholesale cost of petrol has reduced significantly.
“This is sadly a classic example of rocket and feather pricing in action, and one which the Competition and Markets Authority will no doubt be looking at very closely.
“It seems as if retailers are making matters worse for themselves by not lowering their forecourt prices despite having a clear opportunity to do so.”
He added: “The only explanation of retailers’ resistance to reducing prices is that they’re protecting profits in case of wholesale costs suddenly going back up.
“Ultimately, the longer they hold out, the more they benefit and the longer the misery continues for drivers struggling with the high prices.”
A 5p per litre reduction in fuel duty implemented by the Treasury in March has not stopped prices from soaring.
The Government has resisted demands for another, deeper cut to help motorists.
AA president Edmund King warned that “crippling” pump prices could “stifle summer staycations” at a time when airports are struggling to cope with demand.
He called on the Government to “urgently take action on price transparency and cut duty levels”.
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