Trump’s legal team filed an official complaint to the US Federal Election Commission, alleging that the “British Labour Party made, and the (Kamala) Harris campaign accepted, illegal foreign national contributions”.

The submission cited media reports that Labour officials, including the prime minister’s new chief of staff Morgan McSweeney, travelled to the United States to advise the Democratic party campaign. They also included a now-deleted LinkedIn post by Labour director of operations Sofia Patel calling for volunteers to travel to North Carolina, and offering to “sort out your housing”.

Foreign nationals are allowed to volunteer in US elections but may not be compensated.

The claim from Trump’s team claim blew up as Starmer jetted to a Commonwealth Heads of Government Meeting (CHOGM) in Samoa, prompting a mid-air rebuttal.

Starmer insisted it was normal for volunteers to campaign and that he had established “a good relationship” with Trump, whom he met for dinner over two hours in New York last month.”The Labour party has volunteers who have gone over (to the US) pretty much every election… They’re doing it in their spare time, they’re doing it as volunteers, they’re staying, I think, with other volunteers over there,” he said.