Sir Keir Starmer has insisted his relationship with Donald Trump is not in jeopardy after the presidential candidate’s campaign claimed the Labour Party was interfering in the US election.

A statement on Mr Trump’s website, DonaldJTrump.com on Tuesday night announced an official complaint had been filed with US federal election officials, and claimed the Labour Party had “made, and the Harris campaign has accepted, illegal foreign national contributions”.

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

Asked if it was a mistake for senior staffers to have met with the Harris campaign, Sir Keir 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.”

Defence Secretary John Healey also sought to play down the row and the potential impact it could have on the transatlantic relationship.

“This is in the middle of an election campaign, that’s the way that politics works,” he said at a press conference in London.

He said the “special, deep relationship” had “withstood the political ups and downs on both sides of the Atlantic and we are determined to make that work in future”.

A Labour Party spokesperson said: “It is common practice for campaigners of all political persuasions from around the world to volunteer in US elections.

“Where Labour activists take part, they do so at their own expense, in accordance with the laws and rules.”

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 linked complaint addressed to the Federal Election Commission refers to reports by The Telegraph newspaper with regards to people associated with Labour going to the US to campaign for Ms Harris.

The letter also refers to a report in the Washington Post which claims that advice has been offered between the Labour Party and Ms Harris’ campaign, and other reporting regarding meetings between senior Labour staff and the Democratic campaign.

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

Sir Keir met with Mr Trump, the Republican presidential nominee, during a trip to New York last month.

The Prime Minister visited Trump Tower for talks ahead of the US election, and said he wanted to meet Mr Trump face-to-face because “I’m a great believer in personal relationships on the world stage”.