THE UK Government has been told crackdown on petrol retailers for “fleecing” customers.

It comes as diesel prices hit a new high, with firms accused of bumping up profits by failing to pass on nearly half of the Chancellor’s 5p fuel duty cut.

Figures from the Department for Business, Energy and Industrial Strategy show the average price of a litre of diesel at UK forecourts was 179.7p on Monday. That was up from 178.4p a week earlier.

The average price of petrol on Monday was 165.1p per litre. That was narrowly below the record of 165.4p set on March 21, based on the Government’s figures.

Separate fuel price statistics by data firm Experian Catalist using a different methodology show average prices on Monday were 180.3p per litre for diesel and 166.8p per litre for petrol.

Rishi Sunak implemented a 5p per litre cut in fuel duty on March 23.

The RAC said retailers are taking an average profit of 2p per litre more than before the policy was introduced to help cash-strapped motorists.

Simon Williams, the RAC’s fuel spokesman, told the Times: “It is hard to explain why retailers appear to be taking more margin now than before the Chancellor’s duty cut in March. It does seem like some of the duty cut is being swallowed up by increased profits.”

The National: Rishi Sunak's fuel duty cut is not being passed on to customers Rishi Sunak's fuel duty cut is not being passed on to customers

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The firm’s analysis showed the average margin for a litre of petrol and diesel is currently 11p and 8p respectively.

In the month up to the duty cut it was 9p for petrol and 6p for diesel.

Tory MP Robert Halfon, who has campaigned for fuel duty cuts, demanded action from his party’s leadership.

“These companies are fleecing motorists along with the major oil companies and seem to be the only people doing well out of the war in Ukraine and the cost-of-living crisis,” he told the Times. “It is high time that the government set up a pump-watch regulator to ensure fair prices.”

AA president Edmund King added: “The chancellor was trying to be generous and give drivers something back with the 5p cut in duty but unfortunately that hasn’t been reflected at the pumps. Time and time again we see the ‘feather and rocket’ effect, where global prices go up and overnight they’re reflected at the pumps. When it’s the other way round, it takes an awful lot longer. In some countries they make it mandatory to flag the wholesale price so motorists can see if the retail price reflects it.”

A Government source said minister expected to “pass on the cut, not profit from it”.

Sunak told Tory MPs on Monday: “Things are difficult and will become even more so in the coming weeks and months when it comes to the economy. Make no mistake, my number one priority in the face of this difficulty is to help the most vulnerable families.”