Washington DC - Donald Trump and his campaign have accused members of the UK's Labour Party of trying to interfere with the US presidential election by campaigning with his rival Kamala Harris.

On Monday, Trump campaign attorney Gary Lawkowski filed a complaint with the Federal Election Commission, urging the agency to conduct "an immediate investigation into blatant foreign interference... in the form of apparent illegal foreign national contributions."

The complaint – which notably spelled Britain wrong – alleges that senior Labour Party members have been in contact with Harris' campaign, and some have traveled to the US to act as advisors.

It cited a since-deleted LinkedIn post shared by Sofia Patel, the Labour Party's director of operations, in which she suggests the party could help the travelers "sort out your housing."

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Lawkowski suggests the post indicates that the party is funding the Harris campaign, claiming "interference is occurring in plain sight."

British Prime Minister and party member Keir Starmer told Sky News that he has a "good relationship" with Trump but pointed out that party members supporting US politicians in election cycles is common, and members this year are doing so voluntarily and without party assistance.

The legal move comes as Trump and his campaign have been laying the groundwork to deny the results of the election if he loses on November 5.