Voting is drawing to a close in the US election, as Donald Trump and Kamala Harris vie to the be next president.

The neck-and-neck race will have a sweeping impact on global politics, including in the UK where Sir Keir Starmer’s Government may have to grapple with upheaval in America’s security and defence approach if Mr Trump wins.

The Government has been working hard to win over the Republican candidate in case he is re-elected, after a trans-Atlantic spat developed in recent weeks over Labour Party volunteers heading to the US to campaign for his rival.

Sir Keir is expected to be following the results of the US election, but his official spokesman did not say whether the Prime Minister would be staying up overnight to watch the results roll in.

Some Cabinet ministers have in the past made scathing criticisms of Mr Trump while Labour was in opposition, including Health Secretary Wes Streeting, who in 2017 called Mr Trump an “odious, sad, little man” in a social media post.

Though Labour and Mr Trump “may not be ideological bedfellows”, if he is elected “there will be a really good working relationship”, the Health Secretary told LBC.

The Republican candidate would likely chart a new US course on major conflicts in Ukraine and the Middle East, areas where Sir Keir has largely followed the lead of US President Joe Biden.

Dr Leslie Vinjamuri, the director at Chatham House’s US and Americas programme, told the PA news agency Mr Trump would push European Nato members to hike their defence spending commitments, as well as calling for a peace deal between Ukraine and Russia.

A pro-Israel stance in the Middle East conflict which may not take into account the Palestinians is also likely to clash with British foreign policy.

“The bottom line, if there’s a Trump administration, is on the security front there is going to be a demand to spend more and to line up,” Dr Vinjamuri said.

A Harris presidency would be more likely to value the long-standing UK-US relationship as “trusted allies”, the expert said, but added there was no guarantee she would be a continuity Biden figure due to the “transitional” period of conflict and turmoil across the globe.

Former Conservative prime minister Boris Johnson has meanwhile weighed in on the American election, claiming it is a “beautiful thing” not to know what will happen when the votes are counted.

Appearing as a guest on Channel 4’s US Election coverage, he said: “Nobody knows what is going to happen, it’s a fantastic thing, it’s a beautiful thing because there are countries where they have democratic elections where they know full well what is going to happen.”

But Mr Johnson also voiced concerns about what the result might mean for global affairs, adding: “The thing that really worries me right now is Ukraine and the future of democracy in that country. I think there is a risk whatever happens in this election that there will be a disaster in Ukraine.”

In central London, Democrat supporters living in the UK appeared confident their efforts to “get out the vote” of Americans overseas was “second to none”.

Democrats Abroad UK chair Kristin Wolfe told PA: “This is happening all over the world – we are turning out overseas voters.

“We’re going to win this thing.”

So-called swing states such as Arizona, Georgia and Pennsylvania – where the results will be close – are the areas where the Democrats and Republicans have focused their campaigning in recent days.

Under the US voting system, a total of 270 votes in what is known as the electoral college are needed to win the presidential election.

Ms Harris narrowly leads Mr Trump in the final prediction by YouGov ahead of the US election, with the pollster predicting she has 240 electoral votes, Trump 218, while a further 80 remain uncertain.

Key issues in the race to be the next US president include security on the US’s southern border with Mexico, abortion rights and reducing inflation.