Sir Keir Starmer’s trade deal with Donald Trump risks favouring Jaguar Land Rover (JLR) and “squeezing out” smaller carmakers, the boss of Aston Martin has claimed.

Adrian Hallmark said changes to the UK-US agreement were urgently needed “so we don’t get squashed and so that it doesn’t become a JLR tariff agreement”.

The chief executive’s comments, reported by Bloomberg, concern the trade deal’s arrangements for British cars shipped to America under a new quota system that came into effect this month.

Under the deal, tariffs on British cars have fallen from 27.5pc to 10pc. But this is only for the first 100,000 cars per year, or 25,000 cars per quarter.

It has also recently been confirmed that this quota will be allocated on a “first come, first served” basis, triggering fears that carmakers will be forced to race against each other to get vehicles out of factories and on to ships first – or face higher taxes than their competitors.

JLR shipped more than 120,000 cars to North America in 2024, according to published sales figures. Aston shipped about 2,000.

On Wednesday, Mr Hallmark called on the Government to impose limits for different categories within the quota. For example, he said some of the quota should be reserved for the type of high-end supercars that Aston and competitors produce.

The marque also competes with the likes of JLR, Lotus, Rolls-Royce and Bentley in the lucrative luxury SUV market with its DBX model.

The stakes for these brands are high because once the quota is taken up, they must go back to paying the 27.5pc tariffs Mr Trump previously imposed in April.

Such levies have proved expensive for companies exporting from the EU, which is scrambling to get a deal with Mr Trump over the line to reduce the rate to 15pc.

Vauxhall owner Stellantis has said it expected to pay €1.5bn (£1.3bn) in tariffs this year. Separately on Wednesday, Mercedes-Benz and Porsche said tariffs would cost them €362m and €400m respectively for the first half of 2025 alone.

Earlier this month, Mike Hawes, chief executive of the Society for Motor Manufacturers and Traders, said there was a “general feeling” among carmakers “that the tariff quota we have is sufficient to meet the demand for this year” but the industry wanted it to grow year on year.

However, at the moment there is no indication that the quota will be increased.

Mr Hawes added: “They’re reasonable quotas, given our export volumes. Obviously we would like to see that increase … but at least it gives you a basis to start from.

“Different brands will have different strategies, wherever they are on the product cycle for next year, and we know there are some new products coming next year.”

He admitted there was a possibility that carmakers might seek to beat each other to the quota and that there was probably “some paranoia” about that in the industry.

But he claimed such a scenario was “unlikely, because if you try and put one over on your competitors, you’re going to damage that same supply chain, because it’s shared among so many of these manufacturers”.

Sir Keir visited the Midlands headquarters of JLR in May when he announced his “landmark” trade deal with Mr Trump and vowed to protect jobs.

However, just weeks later the carmaker said it would cut 500 jobs in what was described as “a personal embarrassment” for the Prime Minister.

A government spokesman said: “We are working with industry to ensure the quota works effectively and fairly, and will ensure the UK remains a top destination for investment in automotive manufacturing through our Plan for Change.”

JLR was approached for comment on Wednesday.

Mr Hallmark’s remarks came as Aston confirmed a 25pc drop in sales during the first half of 2025, blaming both US tariffs that were announced in April and lower deliveries of “specials” – the ultra-expensive and highly profitable one-off models it produces.

The company sold 1,922 in the first six months of this year, down from 1,998 in 2024.

But revenues fell 25pc to £454m and profit margins shrank from 39pc to 28pc, reflecting the less profitable sales mix. Half-year losses fell from about £217m to £141m.

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