Trump rallies in Georgia ahead of Harris’ CNN Town Hall: Live updates on the 2024 election

Prime Minister Keir Starmer denied the allegations and said Labor activists had worked unpaid in several American elections. Mr. Starmer, who had dinner with Mr. Trump during a recent visit to New York, said the issue would not poison their relations if Mr. Trump were elected.

“As prime minister of the United Kingdom, I will work with whoever the American people choose to return as their president in their elections, which are now very close,” Mr. Starmer told reporters en route to a diplomatic meeting in Samoa.

Mr Starmer said Labor activists volunteered in their free time and not as party employees. The party said she would be expected to cover her own travel expenses and accommodation, which in the United States are typically provided by Democratic campaign volunteers. “It’s really simple,” Mr Starmer said.

But Trump campaign lawyer Gary Lawkowski argued in the complaint that the donation of time and services by British volunteers amounted to an “illegal donation by foreign nationals” to the Harris campaign. He also cited conversations between senior Labor strategists, including Morgan McSweeney, who is now Mr Starmer’s chief of staff, and advisers to Ms Harris.

“When representatives of the British government previously attempted to go door-to-door in America, it did not end well for them,” Lawkowski wrote, pointing to the recent 243rd anniversary of the surrender of British troops after the Battle of Yorktown in the Revolutionary War. “It appears that the Labor Party and the Harris presidential campaign have forgotten the message.”

Mr Trump himself did not raise the issue of Labor volunteers. But he is no stranger to transatlantic politics – in both directions.

As president in 2019, Mr. Trump called into a London radio show hosted by Nigel Farage, a right-wing politician, to offer full support to Boris Johnson, who was then prime minister and had just called a general election. He also sharply criticized the then Labor leader Jeremy Corbyn.

“He would be so bad, he would treat you so badly,” Mr. Trump said of Mr. Corbyn. “He would take you to such bad places.”

An aggrieved Mr Corbyn wrote on social media at the time: “Donald Trump is trying to interfere in the UK election to get his friend Boris Johnson elected.”

Mr Farage, who now holds a seat in Parliament and leads the anti-immigrant Reform UK party, has also campaigned for Mr Trump. In the final week of Mr. Trump’s failed re-election campaign against President Biden in 2020, Mr. Trump greeted Mr. Farage on stage at a rally in Goodyear, Arizona.

Mr Farage initially announced he would skip the recent British general election because he wanted to focus on helping Mr Trump win back the White House. “I intend to help the grassroots campaign in the US in any way I can,” he posted on social media before changing course a week later.

Mr Starmer has tried to avoid the American election, although he met with the former president when he was in the United States in September to attend the United Nations General Assembly. He has not spoken publicly about the meeting other than to say that he and Mr. Trump had a “good relationship.”

Mr. Trump’s allies distinguish between supporting a candidate, which they say is an exercise in free speech, and organized advertising. In his campaign, he cited a voluntary effort by the Australian Labor Party in 2016 to support the election campaign of Vermont Sen. Bernie Sanders.

The election commission found that these efforts violated a ban on foreign donations. But unlike the British Labor Party, the Australian party covered the travel costs of its volunteers and also gave them a daily stipend.

The Trump campaign’s letter was apparently provoked by a now-deleted LinkedIn post from Sofia Patel, a senior Labor Party official. “I have nearly 100 (current and former) Labor Party staff traveling to the US in the next few weeks, to North Carolina, Nevada, Pennsylvania and Virginia,” the post reads. “I have 10 spots available for anyone who wants to travel to the battleground state of North Carolina – we’ll take care of your accommodations!”

The campaign also cited meetings between Labor and advisers to Ms Harris which it said had resulted in “generously borrowed language and themes from prominent Labor Party officials”.

In an interview last month, Jonathan Ashworth, a former Labor MP, said that he and other officials, including Mr. McSweeney and Matthew Doyle, Mr. Starmer’s communications adviser, spoke with Harris officials and other Democrats at the Democratic National Convention in Chicago .

“There was a lot of interest in how we won our campaign,” Mr Ashworth said. He said that when it came to immigration, they advised Harris officials to emphasize the need for strong law enforcement. Mr Starmer had promised during his own election campaign to break up the gangs smuggling migrants across the English Channel.

Mr. Ashworth said he also warned Democrats not to be complacent amid anger among pro-Palestinian voters over the Biden administration’s stance on the war in Gaza. He spoke from personal experience: He lost his seat in the recent election due to a backlash against the Labor Party, which critics say was too slow to condemn Israel’s killing of Palestinian civilians in military combat.

“The anger wasn’t captured in the survey,” Mr Ashworth said. “You have to make sure that people don’t stay at home because of Gaza.”

Labor officials said neither Mr. McSweeney nor Mr. Doyle were in Chicago to advise or assist the Harris campaign. The party covered Mr. McSweeney’s spending, while Mr. Doyle’s spending was covered by the Progressive Policy Institute, a center-left think tank in Washington.

Political analysts in Britain said the dispute appeared to have been largely aimed at portraying Ms Harris as a far-leftist. In a statement on Tuesday, a top Trump campaign aide, Susie Wiles, said: “The far-left Labor Party inspired Kamala’s dangerously liberal policies and rhetoric.”

Labor activists have long traveled to the United States during presidential campaigns. Natalie Fleet, a newly elected Labor MP, recalled campaigning for Hillary Clinton as a young volunteer in Ohio in 2016.

There is also a long history of ties between British and American political advisers, sometimes making strange bedfellows: In 2013, Jim Messina, a Democratic adviser and campaign manager to President Barack Obama, signed on as an adviser to the British Conservative Party. His former colleague David Axelrod advised Labour.

“English politics is not comparable to that of the United States in its policy positions,” Mr. Messina said at the time. “Conservatives in the United States are not Republicans.”