27th September 2026
There are increasingly alarming headlines about the possibility of diesel reaching £2.50 a litre, or even higher, in Britain.
The immediate trigger is the threat of restrictions on US diesel exports. President Donald Trump has backed the idea of restricting exports as American diesel prices have reached record levels.
For Britain, this matters because the United States has become an important source of diesel. But there is a considerable difference between a possible US export restriction and an actual ban.
So how worried should British motorists and businesses be?
The threat is real, but a ban has not happened
The story began earlier this week when President Trump said he supported the idea of stopping or restricting diesel exports to help bring down prices in the United States.
US Treasury Secretary Scott Bessent subsequently said officials were examining whether such a measure could work.
That immediately raised concerns in Europe because the US is now one of the world's largest exporters of diesel and other middle-distillate fuels.
However, the position has been less definite than some headlines suggest.
On September 23, a White House official denied a report that the US was preparing a 90-day diesel export ban. Energy Secretary Chris Wright also said that nobody was considering a blanket ban and that discussions were instead looking at ways of getting more diesel into the United States while maintaining flows of petrol and jet fuel.
In other words, there is currently no confirmed US diesel export ban.
That distinction is important when considering what might happen next week.
Britain really is exposed to US diesel
There is nevertheless a genuine reason for concern.
The UK Government's latest statutory security of supply report says Britain imported diesel from 28 different trading partners in 2024.
The United States supplied 35.5% of those imports, while the Netherlands and Belgium together supplied another 37%.
That means the UK is not dependent upon one country, but losing a source responsible for more than a third of annual diesel imports would still be a significant shock to the market.
The Government itself describes the UK as favourably positioned to obtain diesel from a diverse range of sources. UK refineries also continue to produce diesel, although domestic production met only about 55% of road diesel demand in 2024.
The US Energy Information Administration puts the scale of the trade into perspective. UK imports of US distillate averaged about 81,000 barrels a day in 2024, compared with only 23,000 barrels a day in 2021.
So Britain's reliance has increased substantially.
The bigger problem is that the diesel market is already tight
This is perhaps the most important part of the story.
Britain is not facing a potential US export restriction in an otherwise normal fuel market.
Global diesel supplies are already under pressure.
Disruption to oil and refined fuel supplies associated with the conflicts involving Russia, Ukraine and the Middle East has reduced the amount of diesel available to international markets.
European diesel prices have already risen dramatically and refineries in several parts of the world are operating under considerable pressure.
That means Britain would be trying to replace US supplies at exactly the time when other buyers around the world are also looking for diesel.
This is why a US export ban could have an immediate effect on prices even if there were still plenty of diesel physically available somewhere in the world.
Would Britain suddenly run out of diesel?
Probably not.
The first effect of losing US supplies would more likely be higher prices rather than empty filling stations.
Oil companies and fuel traders would look for alternative supplies from other countries. Britain already imports from a wide range of sources.
But replacement cargoes would have to be bought in a competitive international market.
If several countries were trying to replace American diesel at the same time, the price of those alternative supplies could rise sharply.
That higher wholesale cost would then work its way towards filling stations, businesses and ultimately consumers.
The UK Government says its fuel supply is supported by domestic refining and imports and that it monitors forecourt stock levels as part of its security-of-supply arrangements. It reported no significant national fuel-supply disruption during 2024.
So the immediate concern is not necessarily that Britain would have no diesel.
It is that the diesel available could become much more expensive.
Where does £2.50 a litre come from?
This is where some of the headlines need to be treated carefully.
UK diesel was already averaging close to £2 a litre in the latest reports. OilPrice, quoting recent RAC figures, reported an average of 197.31p a litre on September 23, with the RAC warning that £2 a litre was highly likely to be breached.
Against that background, analysts have discussed £2.50 a litre as a possible consequence of a US export restriction.
But £2.50 is a scenario, not a forecast.
One group of analysts described such an increase as not unreasonable under a ban, while other commentators have discussed prices above £3.
Those figures depend upon what the United States actually does, how long restrictions last, how much diesel can be sourced elsewhere, what happens to oil prices and how international traders respond.
There is therefore a danger of turning a possible worst-case scenario into something that sounds like a prediction.
It isn't one.
There could even be a downside for America
There is an interesting complication to the proposed US policy.
Diesel is produced alongside other petroleum products during the refining process.
If American refiners suddenly found themselves unable to export surplus diesel, they could eventually have to reduce refinery production.
That could reduce supplies of other fuels such as petrol and jet fuel as well.
Reuters reported that Energy Secretary Chris Wright had already warned that a blanket export ban could have wider consequences for American fuel markets.
In other words, restricting exports might not be a simple case of keeping American diesel at home and making it cheaper for American motorists.
The consequences could spread through the entire refining system.
Russia is also adapting to the attacks
There is another development worth watching because it could affect the longer-term diesel market. Russia has begun commercial shipments from the new Arctic Sever Bay terminal as part of its huge Vostok Oil project.
Initial flows are reported at around 150,000 barrels a day, with plans to increase this to about 600,000 barrels a day by late 2027. The project gives Russia another export route that is much less exposed to Ukrainian attacks on its western oil infrastructure and ports.
However, there is an important distinction. Vostok Oil produces crude oil, not diesel. Russian refineries are still being damaged by Ukrainian attacks, and this is reducing the country's ability to turn crude into diesel and other fuels. So Russia may increasingly be able to move crude to Asian customers even while its refining system comes under pressure.
For Britain and Europe, that could mean the international oil market remains well supplied with Russian crude while the market for refined diesel becomes considerably tighter. In the complicated energy market created by the war, having oil available does not necessarily mean having enough diesel available.
What could it mean for Caithness?
For Caithness, another substantial increase in diesel prices would matter because diesel is not simply a motorist's fuel.
It is a business input.
Haulage companies use it to move goods to and from the north.
Farmers depend on diesel for tractors and other machinery.
Construction companies use diesel-powered equipment.
Fishing vessels and other commercial operators face fuel costs.
Delivery companies, tradespeople and many other businesses also depend on diesel.
The cost eventually finds its way into other prices.
A lorry carrying food, building materials or consumer goods from central Scotland to Caithness has to pay for fuel. If that cost rises substantially, somebody has to absorb it.
For a rural area with long distances between suppliers and customers, the effect can be more noticeable than in areas where businesses and consumers have shorter journeys and more alternatives.
And what about heating oil?
There is also a reason for households in rural Scotland to keep an eye on the situation.
Heating oil is not the same product as road diesel and the retail prices do not simply move in lockstep.
But both are middle-distillate petroleum products and are influenced by the wider international refining market.
A prolonged diesel shortage therefore has the potential to add pressure to other oil-based fuels as well.
For households already facing higher energy costs, that is another reason to watch the market.
What should we watch next week?
There are several things that will tell us much more than the most dramatic headlines.
First, whether the US Government actually announces restrictions on diesel exports.
Second, whether any restrictions are temporary, partial or a complete ban.
Third, how quickly European traders find alternative supplies.
Fourth, what happens to wholesale European diesel prices.
And finally, whether those wholesale increases start appearing at British filling stations.
These will tell us far more about where pump prices are heading than a headline predicting £2.50 or £3 a litre.
No need to panic-buy
There is a genuine diesel problem developing internationally and Britain is unusually exposed to the American market.
But that is different from saying that Britain is about to run out of fuel.
The UK has multiple sources of supply, domestic refining capacity and established emergency arrangements.
The more immediate risk is a price shock if American exports are restricted while the international diesel market is already tight.
For motorists, farmers and businesses in Caithness, that is certainly something worth watching.
But there is a useful distinction between preparing for higher prices and panicking about shortages.
At the moment, the evidence points much more strongly towards uncertainty and price risk than towards British filling stations suddenly running dry.
The coming week should tell us whether the American diesel threat remains political rhetoric, becomes a limited export restriction, or develops into something much more serious.