CMA fuel pricing watchdog flags slow diesel pass-through and sends over 1,100 warnings

19 Aug 2026

The Competition and Markets Authority (CMA), the UK’s CMA fuel pricing watchdog, has warned that many petrol stations are still too slow to pass on falls in wholesale fuel costs to drivers, and has revealed it sent 1,166 letters and 53 compliance notices to retailers since April over failures to register with the Government’s Fuel Finder price comparison scheme.

The CMA published the findings in its latest quarterly update on the road fuel market. A quarterly update is a regular, scheduled check-in that the regulator publishes to track how petrol and diesel prices are moving relative to the wholesale costs retailers pay to buy fuel in bulk.

What the CMA fuel pricing watchdog actually found

The regulator identified what it called ‘passive pricing strategies’ among the majority of retailers. In plain terms, this means retailers are quicker to push prices up when wholesale costs rise than they are to bring prices down when those costs fall. The CMA found that between May and June, some retailers did not immediately reduce diesel prices at the pump when wholesale diesel costs dropped, which it said could have sharpened competition in the market.

Overall, pump prices did fall during June, but the CMA said they remained significantly higher than before the Middle East conflict began. Retailer profit margins were described as being at or above the historically high levels seen in 2025. The watchdog was careful to note, however, that it found no evidence of deliberate profiteering on the back of the war in Iran.

Sarah Cardell, chief executive of the CMA, said: ‘We know prices at the pump are putting real pressure on drivers’ pockets and our monitoring plays an important role in giving drivers confidence that retailers are not taking advantage of the conflict in the Middle East. We will continue to monitor prices and margins closely and expect any reductions in wholesale prices to be rapidly and fully passed on to drivers.’

Fuel Finder registrations and the road ahead

The Government-run Fuel Finder scheme, which lets drivers compare prices at nearby forecourts before they fill up, now covers around 97% of petrol stations, accounting for roughly 99% of all fuel sold in the UK. The scheme is operated by the Government alongside technology company VE3. The CMA said it had not yet needed to issue any fines, though it has used its compliance notice powers in 53 cases.

Fuel Finder was created following a CMA recommendation in July 2023, after the regulator found that competition among retailers had weakened since 2019 and that drivers had paid nearly £1 billion more for fuel at supermarkets during the previous year because of increased margins.

The CMA said it would ‘actively monitor’ the market and carry out a more detailed review in the autumn to check that customers are paying a fair price across the UK.

The AA’s response: supermarkets in the frame

The AA welcomed the CMA’s update but said it exposed continuing failures. Edmund King, the AA’s president, said: ‘Clearly, some fuel retailers are prepared to pass on lower costs promptly and help their customers. But many more, including large numbers of supermarkets, are not.’

King highlighted that some forecourts were charging petrol at 10p a litre less than nearby rivals, illustrating the gap that passive pricing can create for drivers in the same area. He also pointed to a 10p-a-litre drop in wholesale petrol costs in late July and early August that had ‘barely registered at the pump’, with the UK average price falling by just 0.4p a litre over seven days to reach 161.2p. He added that wholesale petrol costs had since partially rebounded but still remained 1p to 2p a litre below the peaks seen in mid to late July.

King described Fuel Finder as ‘a start in getting drivers to fight back against stubbornly high petrol and diesel prices’. The CMA’s autumn review will be the next concrete moment at which the watchdog can decide whether to escalate its response, including the use of fines for non-compliant retailers.

Brendan Carey

Brendan Carey spent sixteen years in education before he started writing about it. He trained as a secondary school computing teacher, ran an ICT department for a decade, and spent his last years as a digital learning lead at a multi-academy trust trying to get procurement budgets to match curriculum ambitions. He writes about edtech, digital skills, curriculum policy, and the reality of teaching technology in schools where the Wi-Fi drops out during inspections. He knows what works in a classroom and what works in a sales demo, and they are rarely the same thing. Brendan lives in Leeds. He has opinions about the computing curriculum that he considers constructive and Ofsted would consider robust.