Ben Caswell, Neisr’s senior economist, said: “Whilst the new trade deal with the US constitutes a political win for the Government, the direct impacts on UK GDP are likely to be very small, given we export just £9 billion worth of cars to the US each year and the vast majority of goods won’t benefit from this tariff relief announcement.”

But the prime minister was clear he has his own way of doing things.“I am the sort of person that tries to have constructive and positive relations with people,” he said. “I don't really believe in slamming doors and that sort of way of doing politics.