Fears that the US could restrict diesel exports have added another potential threat to Britain’s already stretched fuel market.

America accounts for around a third of the UK’s diesel imports.

Trump has raised the idea of a diesel export ban to help reduce pump prices in the US ahead of the upcoming elections.

Trumpian solutions

Reports have emerged that Washington was considering a 90-day ban on diesel exports as US diesel prices reached record levels amid disruptions to global oil and fuel supplies.

Speaking in New York before the UN General Assembly, President Donald Trump told reporters he would back a ban on US diesel exports.

He has come under increasing pressure from Republican politicians to block US diesel exports to bring down prices ahead of the midterm elections in November.

However, the White House subsequently denied that a 90-day export ban was being prepared, while US Energy Secretary Chris Wright said a blanket ban would not work.

“The blunt tool of banning diesel exports definitely doesn’t work,” Wright said, warning that preventing refiners from exporting could eventually force them to cut production, putting upward pressure on other fuels.

Unstable supplies

Nevertheless, the episode highlights the UK’s vulnerability to international diesel markets.

According to the Government’s latest statutory security-of-supply report, the US supplied 35.5% of UK diesel imports in 2024, making it Britain’s single biggest source.

The latest figures from Fuels Industry UK put the American share at 31% in 2025.

That dependence has increased since Russia invaded Ukraine and the UK’s subsequent ban on Russian oil imports.

The UK now imports around 55% of the road diesel it consumes, compared with just 14% in 2003, according to Fuels Industry UK.

At the same time, domestic refining capacity has fallen.

The closures of the Grangemouth and Lindsey refineries in 2025 reduced Britain’s refining capacity by almost a quarter, increasing the importance of overseas supplies.

Pump pressure

The timing could hardly be more uncomfortable for motorists.

The latest Government weekly figures show average UK diesel at around 197p per litre, following a rise of almost 5p in a week.

Petrol was around 173p per litre.

Diesel is therefore already more than 24p per litre more expensive than petrol, adding substantially to the cost of filling a typical 55-litre tank.

The latest increases come as global diesel markets face an unusually tight supply situation.

Reuters reports that global diesel prices have reached record levels, with disruptions linked to the conflicts in Iran and Ukraine reducing supplies from major producing regions.

European diesel futures have more than doubled since the beginning of 2026, while US diesel prices have also reached record levels.

The United States itself has limited room to increase supply quickly.

Although American refineries have been operating at very high utilisation rates, US diesel inventories remain below their five-year seasonal average.

American influence

For the UK, any sustained reduction in American exports could therefore add competition for diesel cargoes from alternative suppliers and increase wholesale prices.

It would not necessarily mean a one-for-one increase at British forecourts, however.

The UK buys diesel from a wide range of countries, and official Government data says it remains “favourably positioned” to source diesel from diverse suppliers.

Fuels Industry UK’s Elizabeth de Jong said the US debate demonstrated why Britain should not become overly dependent on overseas production.

“The UK continues to need fuels – from transport to chemicals, agriculture and defence,” she said. “The recent discussion in the US around diesel exports has shown once again that we cannot solely rely on overseas production for domestic energy security.”

Uphill journey

RAC head of policy Simon Williams said: “The price of diesel continues to move steadily towards a new all-time high.

“A litre now averages 197.31p across the country, meaning it’s just under 2p (1.78p) from surpassing the 199.09p record set on 25 June 2022, although we’re aware of many forecourts already charging in excess of this.

“With concerns over the global supply of wholesale diesel, the question facing drivers is no longer ‘when will the average price exceed 199.09p?’ but ‘how far above £2 a litre will it climb?’.

“Only a sudden and sustained drop in the cost of oil can prevent an average diesel pump price of over £2 a litre happening, which sadly appears highly unlikely.”

The price of Brent Crude fell slightly this week after talks between the US and Iran, with Iran proposing a joint agreement to open the Straits of Hormuz, though President Trump’s ongoing threat to obliterate Iran led Iranian negotiators to leave the talks.

Dependencies

It is another reminder that pump prices are increasingly influenced by events far beyond Britain’s control, and that in recent years Britain has reduced its abilities to refine oil or store refined fuel stocks.

And although a US export ban is not currently confirmed, the prospect alone highlights how exposed the UK remains to a global diesel market already operating under considerable pressure