29th September 2026
For most British motorists, the immediate problem with diesel is the price.
The average UK price has now reached a record 199.18p a litre, pushing the cost of filling an average family car to almost £110. The previous record was set in 2022 during the energy shock following Russia's invasion of Ukraine.
But there is now a second question which is potentially much more serious:
Could Britain actually run short of diesel?
And if it did, could the Government ration it?
The answer to the second question is yes. Britain already has an emergency system for doing exactly that.
But that does not mean rationing is currently being introduced.
The Government has repeatedly said that its emergency fuel plans are precautionary. In April, ministers said Britain remained well supplied and was not approaching the threshold for activating emergency rationing arrangements.
The circumstances, however, have changed considerably since then.
The US connection
Britain is unusually exposed to changes in the international diesel market.
The country now imports around 55% of the diesel it consumes, compared with only 14% in 2003.
The United States supplied around 31% of Britain's diesel imports in 2025, making it the UK's largest individual source.
That matters because President Donald Trump has been considering restrictions on US diesel exports as American motorists and businesses face their own high fuel costs.
There is no US diesel export ban in force at present.
But even the possibility of one has caused concern in fuel markets.
The UK is reportedly seeking an exemption if Washington does introduce restrictions, while Andy Burnham is expected to lobby the US over the issue.
This is why the situation deserves attention.
Britain isn't simply dealing with an expensive barrel of oil. It is dealing with refining capacity, international supply chains and dependence on imported diesel at the same time.
Britain has fewer refineries
There is another structural problem.
Britain had six working oil refineries in 2024.
It now has four.
Combined crude-processing capacity has fallen from about 1.27 million barrels a day to around 1 million barrels a day.
That does not mean Britain cannot obtain enough fuel.
It does mean that the country has become more dependent on imports to balance its requirements.
The fuel industry has itself warned about this dependence. Fuels Industry UK says that the closure of Grangemouth and Lindsey reduced UK refining capacity by almost a quarter and that the country now imports about 55% of its road diesel.
So what would rationing actually mean?
This is where Britain's emergency plan becomes interesting.
The Government's National Emergency Plan for Fuel contains several measures which can be activated if there is a severe national shortage.
One is a Maximum Purchase Scheme.
That could restrict how much road fuel members of the public could buy at filling stations on each visit. It could also restrict the hours during which fuel could be sold.
In other words, the familiar sight of motorists filling their tanks whenever they want could disappear temporarily.
There is also a Commercial Distribution Scheme, under which road diesel could be prioritised for commercial vehicles and key supply chains such as food and health.
Emergency services, utilities and public transport could also receive priority supplies.
So if Britain ever reached that point, it would not simply be a case of everybody receiving the same amount of diesel.
The Government would try to make sure that the vehicles and industries essential to keeping the country functioning received fuel first.
That could matter enormously in Caithness
Diesel is not simply a motorists' fuel.
In Caithness it is used by farmers, hauliers, taxis, buses, construction companies, fishing businesses, delivery vehicles and generators.
A shortage could therefore become an economic problem very quickly.
Even without formal rationing, a shortage of available diesel could increase the cost of transporting food and other goods.
Farmers could face higher costs for machinery.
Hauliers would face increased operating costs.
Taxi fares could rise again.
And businesses could find themselves paying considerably more simply to keep vehicles moving.
That is why the price of diesel matters far beyond the filling station forecourt.
Price rationing could come first
There is an important distinction between formal rationing and what might be called economic rationing.
At almost £2 a litre, some motorists will already be cutting unnecessary journeys.
Businesses will be looking harder at fuel consumption.
Hauliers will have to pass some of the additional cost through the supply chain.
Agriculture, construction and other diesel-intensive businesses will have little choice but to absorb or pass on some of the increase.
In that sense, high prices themselves reduce demand.
The RAC says diesel prices have risen by around 15p a litre during September alone and warns that further increases are possible if the wholesale market remains under pressure.
Formal rationing would therefore represent a much more serious stage.
It would mean that there was not enough fuel available at any price to allow normal unrestricted sales.
We are not there at present.
Should motorists panic?
Probably not.
The biggest danger at the moment may actually be that fear of shortages creates the shortages people are worried about.
If large numbers of motorists suddenly decide to fill their tanks and buy additional fuel, forecourts can experience temporary shortages even when national supplies remain adequate.
That is why the Government's emergency planning is important.
It provides a mechanism for managing a genuinely serious shortage rather than relying on panic buying.
There is also the possibility that international supply conditions improve. Oil and refined-product markets can move very quickly in both directions.
But the latest developments have changed the calculation.
Britain has fewer refineries than it did two years ago, depends heavily on imported diesel, and now faces uncertainty over one of its biggest overseas sources of supply.
Rationing is possible — but it is not happening
That is probably the most important message.
Britain has a diesel-rationing plan, but there is no evidence that the Government is currently activating it.
The Government's own emergency plan says those controls would only be used in the event of a severe national fuel supply shortage.
So the story today is not that Britain is about to introduce rationing.
It is that the circumstances which could eventually lead to rationing are now receiving considerably more attention.
And for a country increasingly dependent on imported diesel, that is something worth watching.
For Caithness, where diesel is fundamental not only to private cars but to farming, fishing, transport, deliveries and many local businesses, the question is bigger than what appears on the price board at the filling station.
The real issue is whether Britain has enough diesel to keep the economy moving — and who gets it first if supplies ever become tight.