The Business Secretary has ordered an “urgent” investigation into petrol station operators amid concerns some are pocketing the multi-billion cut to fuel duty.

In a letter to the Competition and Markets Authority (CMA), Kwasi Kwarteng wrote that people were “rightly frustrated” that the 5p-a-litre reduction had not stopped prices from soaring.

Noting regional disparities in petrol prices, the Spelthorne MP asked for recommendations to “strengthen competition” in the petrol market by early July.

Mr Kwarteng said: “Drivers should be getting a fair deal for fuel across the UK.

I am writing to you to ask that the CMA conduct an urgent review of the fuel market ... to explore whether the retail fuel market has adversely affected consumer interests

“The British people are rightly frustrated that the £5 billion package does not always appear to have been passed through to forecourt prices.

“I am writing to you to ask that the CMA conduct an urgent review of the fuel market … to explore whether the retail fuel market has adversely affected consumer interests.”

The competition watchdog has previously made Asda and Morrisons sell off a number of forecourts during private equity acquisitions.

Last Tuesday, data firm Experian Catalist revealed the average price of petrol at the pump had reached a record 180.7p.

Jack Cousens, the AA’s head of roads policy, welcomed Mr Kwarteng’s move but called for “more urgent action”.

“To relieve pressure at the pumps we need an immediate 10p cut to fuel duty,” he argued.

“Longer term, the CMA should consider extending the pump price transparency available in Northern Ireland to the rest of the UK.

“The Consumer Council’s fuel price checker stimulates competition and has led to drivers there enjoying the lowest fuel prices in the UK.”