Chancellor John Healey is under renewed pressure to cut fuel duty in this month’s Budget after the price of diesel broke through the £2 a litre barrier.

The crisis over global diesel supplies eased on Friday after G7 leaders agreed to release 100 million barrels of the fuel and oil from reserve stocks.

In return, Donald Trump dropped his threat to impose an export ban on US diesel exports.

High diesel prices will also have a knock-on effect on the cost of food for supermarket shoppers, the Road Haulage Association (RHA) said, warning that a “fuel duty hike is a food price hike”.

Richard Smith, managing director of the RHA, said: “Spiralling costs are a huge challenge for our sector, with hauliers typically paying £350 a week more to fill up an HGV than they did in February.

“This is completely unsustainable, and with no end to global uncertainty in sight, we’re going to see more transport businesses closing their doors as a result of elevated prices, so the Government must act now.

“We urge ministers to pause fuel duty increases set for the new year and scrap plans to link it to the Retail Price Index from April.

“And we’re also calling for a fuel duty rebate for essential users like haulage, coach and van operators that would relieve inflationary pressure and save some firms from going bust.”

Smith added: “Almost everything on a supermarket shelf got there on a lorry. There is nowhere for additional costs to go but onto customers and onto the shelf. Where it can’t be passed on, firms go under.”

Leaders of the G7 group of richest nations held an emergency virtual meeting on Friday afternoon to discuss the US President’s threat of a diesel export ban.

Foreign Secretary Ed Miliband stood in for Andy Burnham, who was at his father’s funeral.

After the talks, French President Emmanuel Macron announced that the leaders had agreed to release 100 million barrels of diesel and oil from energy reserves, coordinated by the International Energy Agency.

Macron said G7 members had agreed to “take no measures to restrict the exchange of energy and petroleum products between partner countries”.

He added: “We agree to work in a coordinated manner to help bring down the prices of petroleum products, particularly diesel.”

Figures released by the RAC on Friday showed that the average price of a litre of diesel rose to a record 200.01p.

A litre of diesel is now on average 57.6p more expensive than at the start of the US-Iran war on 28 February this year, when it cost 142.38p.

The price of unleaded petrol is also continuing to rise and is now an average of 174.71p per litre, up by 41.9p since the beginning of the war, the RAC said.

RAC head of policy Simon Williams said diesel prices were “showing no signs of slowing, heaping more misery onto motorists”, adding: “The cost of filling up an average family car is now £110, almost £32 more than it was at the start of the US/Iran war.

“With electricity and gas bills also rising, household budgets will already be squeezed.

“Drivers will be looking to the government to step in and ease the burden by lowering fuel duty further or reducing VAT in October’s Budget.”

Jonathan Owens, an operations and supply chain expert at the University of Salford, said that while the release of energy reserves would help ease pressure in the short-term, there was now reduced protection against future disruption.

He said: “Releasing emergency stocks can provide an important short-term buffer.

“Additional diesel entering the market could help maintain availability, reduce immediate supply pressures and potentially limit extreme price movements.

“Crucially, it also buys businesses time to adapt their logistics, sourcing and inventory strategies.”

Owens said emergency stocks are “effectively an insurance policy”, adding: “Using them now reduces protection against future disruption until those stocks are replenished.”

He said drawing down on reserves can help manage the “immediate symptoms of a supply shock”, but it does not resolve underlying problems such as around weaker refining capacity and dependence on international energy markets.

“Emergency stocks can provide valuable breathing space, but they are a short-term intervention rather than a long-term solution.”

The Treasury declined to comment on tax outside of the Budget, but said that there would be no rises in fuel duty this year.

A government spokesperson said: “Since the outset of the war in Iran, this government continues to protect the British people and businesses from this crisis.

“This means drivers benefit from the extension of the 5p fuel duty cut, with diesel 11p per litre cheaper until the end of the year than it would have been compared to plans inherited from the previous government.”