On 1 May 2026, the Competition and Markets Authority published its first formal verdict on whether UK fuel retailers had taken advantage of the price spike that followed the start of the US-Israel war with Iran. The headline finding: across the industry as a whole, no.
The CMA said retail fuel margins — the difference between the wholesale cost of fuel and the price paid at the pump — were "broadly unchanged" between February and March 2026. The 10.7p per litre average margin recorded across the period was close to or equal to the average for the whole of 2025. CMA chief executive Sarah Cardell concluded that the data did not suggest "a widespread issue of retailers earning higher margins" since the conflict began.
That is the headline. The detail underneath is more complicated — and considerably more useful to drivers.
The five retailers under the microscope
While the industry-wide picture was reassuring, the watchdog identified five retailers whose margins did rise during the price spike: two supermarkets and three non-supermarket forecourt operators. The CMA has not named them publicly while the work is ongoing, but confirmed it is now investigating why those margins moved upward when the rest of the market held steady.
"We are investigating why and will report further in May." — Sarah Cardell, CMA chief executive
The regulator also flagged a separate anomaly that pre-dates the conflict: a period of higher margins at 12.7 pence per litre in December 2025 and January 2026, before the Strait of Hormuz disruption hit. The CMA is examining that too, and is expected to report on both strands in its next monitoring update.
Crucially, the report situates all of this against what it calls a "historically high" baseline. Even where margins haven't moved during the crisis, they're already elevated compared to the 2015-2019 average that the CMA uses as a yardstick. The watchdog described an "ongoing concern" about the lack of competition in the UK fuel retail market — a finding consistent with its July 2023 market study, and the reason the Fuel Finder transparency scheme was created in the first place.
Why pump prices have risen anyway
If margins haven't widened, why are drivers paying so much more? The answer is in the wholesale market. Brent crude has spent most of the past two months trading above $110 a barrel — with a peak above $126 in late April — as the closure of the Strait of Hormuz cut off about 20% of the world's oil and liquefied natural gas. That is a global supply shock, not a UK retail decision.
The result, drawn from RAC weekly data: petrol peaked at 158.3p per litre and diesel at 191.5p per litre in mid-April, capping 43 consecutive days of rising forecourt prices — the longest unbroken run on record. Both have eased back slightly since but remain dramatically above pre-war levels.
Where prices stand vs. before the conflict: Petrol is currently 24.2p per litre above where it was when the conflict began. Diesel is 46.0p per litre higher. On a 55-litre fill, that's roughly £13 extra for petrol and £25 extra for diesel, every time you fill up.
The 'rocket and feather' question
Not everyone agrees with the CMA's reassuring industry-wide framing. The AA's pump-price spokesman Luke Bosdet pushed back hard, accepting that overall margins may not have widened but arguing that the asymmetry between how prices rise and fall is alive and well.
"Maybe not price gouging, but 'rocket and feather' and the pump-price postcode lottery are as strong as ever. The competition watchdog still has a lot of work to do." — Luke Bosdet, AA
"Rocket and feather" is the CMA's own phrase, coined after its work on retailer pricing during the 2022 invasion of Ukraine: prices that go up like a rocket when wholesale costs rise, but drift back down like a feather when wholesale costs fall. The CMA has now confirmed it is looking specifically at whether that pattern is repeating, comparing the speed of pump price rises against the speed of falls as wholesale costs change.
The AA also pointed out two specific concerns that aren't captured by an industry-wide margin average. First, the wholesale cost of diesel has fallen further than the pump price has fallen — meaning the gap that should have closed hasn't. Second, drivers on motorways are paying up to 20p per litre more than drivers at A-road forecourts a few miles away. RAC's head of policy Simon Williams added that pump prices "haven't fallen at the rate that our analysis of wholesale data indicated they should have".
The number drivers should pay attention to: £9
Buried in the same CMA report — and far more actionable than the gouging verdict — is a single figure that tells drivers exactly how much there is to gain by checking before they fill up.
The watchdog confirmed there are now "significant local variations in price" across the UK, with potential savings of up to £9 per tank for drivers who shop around. That's not a theoretical maximum — it's the actual gap the regulator is observing between the cheapest and most expensive forecourts within reasonable distance of each other.
What £9 a tank actually means: Most drivers fill up around once a week. At £9 a saving each time, that's around £470 a year for a household with a single vehicle, or close to £940 for a two-car household. The CMA's separate estimate is that Fuel Finder will save the average driver £40 a year on average — the £9-per-tank figure shows what's possible at the top end for drivers who actively check.
The local variation point isn't new — the CMA has flagged it in every monitoring report since 2023 — but the size of the gap is. Volatile wholesale prices tend to widen the spread between cheap and expensive forecourts, because some retailers re-price faster than others. In a calm market, the cheapest and most expensive station in a town might differ by 8 or 10p per litre. In the current market, that gap is materially wider.
What the public thinks — and why it matters
The CMA's verdict landed on the BBC's website with more than 1,200 reader comments within hours, the vast majority sceptical. A common thread was the suspicion that retailers raise prices the moment crude rises — on the basis that it costs more to "replace" the fuel in their tanks — but are slower to drop them when crude falls, citing the same logic in reverse. That is, almost word for word, the rocket-and-feather behaviour the regulator is now investigating.
Whether or not the CMA finds rocket-and-feather pricing this time round, the practical implication for drivers is the same. When wholesale prices are volatile, the spread between forecourts widens. The average margin may be unchanged industry-wide; but the price you personally pay depends on which forecourt you happen to drive into — and the difference between the best and worst is now meaningful enough to be worth a few seconds of checking.
What happens next
Three things are worth watching over the coming weeks.
- The CMA's follow-up on the five flagged retailers, due later in May. If any of them are named or fined, that would be the first concrete consequence of the watchdog's stepped-up monitoring.
- The rocket-and-feather analysis. This is the part of the report most likely to identify systemic issues rather than individual ones, and it will draw heavily on Fuel Finder data — the same feed that powers comparison apps.
- Whether wholesale falls feed through to the pump. Brent crude has come down from its late-April peak. The AA and RAC have both said the pump-price reduction has lagged. If that gap doesn't close, expect the regulator and the press to keep asking why.
The Fuel Finder enforcement regime — which began on 1 May, the same day the CMA report was published — gives the regulator new tools to act on what its monitoring finds. Forecourts must now report price changes within 30 minutes, and the CMA can fine those who don't. The combination of accurate, near-real-time data and the willingness to use it is what makes this monitoring round different from the ones that came before.
The practical takeaway: The CMA verdict means there's no industry-wide rip-off — but it doesn't mean every forecourt is treating you the same. The watchdog itself says the gap between local stations is now worth up to £9 a tank. With petrol still 24p above pre-war and diesel 46p above, that gap is the single biggest lever a driver actually controls. A two-minute check before you turn into a forecourt is worth real money in this market.