Nigel Farage ripped into Sir Keir Starmer after Donald Trump accused Labour of interfering in the US election.

The Republican presidential candidate’s campaign last night announced an official complaint had been filed with US federal election officials.

The complaint follows reports of senior Labour officials meeting with Democrat Kamala Harris’s campaign, and party staffers volunteering on the ground for her campaign.

In a post on X, Reform leader Mr Farage said Sir Keir had “already insulted” Mr Trump who could return to the White House in the November 5 ballot.

The Clacton MP also used the post to hit out over the decision to relinquish sovereignty over the Chagos Islands to Mauritius earlier this month.

Mr Farage, who is a close ally of Mr Trump, said: This was a terrible decision by Keir Starmer’s government who have now surrendered the vital Chagos Islands, sent 100 Labour Party campaigners to support Kamala Harris [and] already insulted the incoming Trump administration.”

The PM last night insisted his relationship with Mr Trump was not in jeopardy after the election interference claims.

Asked if it was a mistake for senior staffers to have met with the Harris campaign, he insisted any members of his party were in the US on an entirely voluntary basis, similar to in previous elections.

“That’s what they’ve done in previous elections, is what they’re doing in this election. And that’s really straightforward,” he told reporters as he travelled to Samoa for a meeting of Commonwealth leaders.

Pressed further about whether Labour officials’ involvement in the Harris-Waltz Democrat campaign could jeopardise his relationship with Mr Trump if the ex-president wins re-election, Sir Keir replied: “No.”

He added: “I spent time in New York with President Trump, had dinner with him, and my purpose in doing that was to make sure that between the two of us we established a good relationship, which we did, and I was very grateful to him for making the time.”

After describing the meeting as a “good, constructive discussion”, Sir Keir added: “Of course as Prime Minister of the United Kingdom, I will work with whoever the American people return as their president in the elections that are very close now.”

The statement on DonaldJTrump.com on Tuesday night said that “The Trump-Vance Campaign has filed a Federal Election Commission (FEC) complaint against the Harris-Walz Campaign and the Labour Party of the United Kingdom for illegal foreign campaign contributions and interference in our elections”.

The complaint referecned a social media post, which now appears to have been deleted, in which a Labour staff member said there were “nearly 100 Labour Party staff (current and former) going to the US in the next few weeks” to swing states and adding there were 10 more spots.