Nigel Farage points out Labour's 'major political mistake' after Donald Trump files complaint

It also references reports of Labour strategists offering advice to Kamala Harris's campaign and meetings between senior Labour staff and the Democratic team.

Speaking to GB News, Farage said: "There's an even bigger point here which is it is likely, if you believe the betting markets, that Trump is going to win on November 5.

"Our relationship with America when it comes to intelligence, when it comes to defence, when it comes to commerce, is our most important relationship in the world.

"For a governing Labour Party to be seen officially acting on behalf of a rival candidate to the man that's going to win is a very major political mistake. "

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When asked if his comments made him a "hypocrite" because Farage has attended multiple Trump rallies, the Reform UK leaders explained that is not the case.

He said: "I spoke in 2016 at a major Trump rally, and I did say, 'now I know it would be wrong of me to tell you how you should vote, but this is what happened in Brexit. Never underestimate, the fact that actually the polls can be wrong'.

"I wasn't paid to do this. The Labour Party today are trying desperately to backtrack by saying people will be going at their own personal cost."

Labour has attempted to downplay the situation. A party official told Politico: "It says a lot about the current level of political discourse on both sides of the Atlantic that an innocuous LinkedIn post from a party staffer has turned into a diplomatic event."

Richard Grenell, former US Acting Director of National Intelligence under Trump, told the BBC: "We don't want to have any foreign interference in our elections.

"So I think this is a pretty open and shut case: don't interfere in the American elections and you won't be sued."

Labour insists it is not funding travel or accommodation for volunteers, staying within US federal election rules.

These stipulate foreign volunteers cannot spend more than $1,000 helping candidates.

Elon Musk, who has endorsed Trump, called the Labour involvement "illegal".

However, there is no evidence of financial contributions from Labour to the Democratic campaign.

A Labour Party spokesperson told GB News: "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."