Sir Keir Starmer would welcome a visit by Donald Trump to Parliament, Downing Street has said, describing the president-elect as a “steadfast” supporter of the UK-US “special relationship”.

The Prime Minister congratulated the Republican politician on a “historic election victory” after American voters returned him to the White House on Wednesday.

Number 10, which is seeking to build bridges with Mr Trump after his campaign filed a legal complaint about Labour activists backing rival Kamala Harris, said Sir Keir looked forward to speaking with him in “due course”.

Asked if the Prime Minister had spoken with the president-elect following Wednesday’s result, his official spokesman said: “Hopefully the president-elect is getting some well-deserved rest right now but the Prime Minister obviously looks forward to speaking to him in due course.

“He knows first-hand how busy the first couple of days are after winning an election.”

On whether Sir Keir would be open to Mr Trump addressing Parliament, as new Opposition leader Kemi Badenoch proposed in her debut sparring match at Prime Minister’s Questions, Number 10 said matters relating to the House are “for the Speaker”.

However, his spokesman added: “I think questions for the House are for the Speaker, but clearly the Prime Minister would of course welcome a visit from President-elect Trump to the UK in the future.”

Asked whether he would also welcome a visit by Mr Trump to Parliament, the spokesman said: “And to Parliament, but clearly parliamentary matters are one for the Speaker.”

Diplomatic relations between the Labour administration and the new US leader may prove strained as senior party figures, including the Foreign Secretary, have previously been strident in their criticism of him.

But Downing Street on Wednesday stood by David Lammy, who previously described the Republican politician as a “neo-Nazi” sympathiser, confirming that he would remain in post for the rest of the parliamentary term.

Donald Trump visit to Ireland
Former US president Donald Trump will return to the White House after winning the 2024 election (Brian Lawless/PA)

Concerns have also mounted about the prospect of a UK-US trade deal in light of Mr Trump’s proposal to impose hefty tariffs on American imports.

Number 10 refused to be drawn on “future policy discussions” when asked on Wednesday whether such an approach would damage the UK economy, but insisted the Government is confident in standing up for Britain’s interests.

“We look forward to working with President-elect Trump including on a wide range of his policy priorities to improve the UK-US trading relations and to support the significant investment relationship that supports millions of jobs across our two countries,” Sir Keir’s spokesman said.

Mr Trump has refused to explicitly say if he wants Ukraine to win the war with Russia, insisting he wants the conflict to end “in a day” but declining to set out the specifics of how this would be achieved.

Sir Keir has said the UK’s support for Kyiv will remain “ironclad” in the wake of the former president’s election win.

Volodymyr Zelensky visit to UK
Donald Trump has refused to explicitly back Ukraine following Russia’s invasion (Kin Cheung/PA)

“President-elect Trump has been a steadfast supporter of the special and enduring relationship with the US and the UK have enjoyed for many years,” his spokesman said.

“We welcome sustained bipartisan US support for Ukraine which has been absolutely key in the international effort, and the UK’s support for Ukraine will remain ironclad.

“This is obviously among many issues that the Prime Minister looks forward to working with the president-elect on in the coming months and years ahead.”

At Prime Minister’s Questions in the Commons on Wednesday, Sir Keir said: “As the closest of allies, we stand shoulder to shoulder in defence of our shared values of freedom, democracy and enterprise.

“From growth and security to innovation and tech, I know that the UK-US special relationship will continue to prosper on both sides of the Atlantic for years to come.”

Mr Trump’s victory was used as ammunition by Tory leader Ms Badenoch in her first sparring match with Sir Keir across the despatch box, where she urged the PM to apologise for Mr Lammy’s 2018 description of the president-elect.

The Foreign Secretary had called Mr Trump a “woman-hating, neo-Nazi-sympathising sociopath” who is “a profound threat to the international order”.

Ms Badenoch also called on Sir Keir to back an invitation for Mr Trump to address Parliament and revive talks on a UK-US trade deal.

Sir Keir said: “Of course we will discuss issues of our economy with the president-elect, as we already have done.”

Mr Trump declared he had won a “magnificent victory for the American people” once it was clear he was on track to return to the White House as 47th president of the United States early on Wednesday.

That victory was later confirmed as a win in Wisconsin tipped him over the 270 electoral votes needed to defeat Ms Harris.

Mr Trump told supporters that “America has given us an unprecedented and powerful mandate”.

He said that he would not let his backers down and that it is “time to put the divisions of the past four years behind us”.

Addressing a campaign party in Florida in the early hours of Wednesday, Mr Trump pledged to “fight” for “every citizen” and promised the “golden age of America”.

He added: “This is a magnificent victory for the American people that will allow us to make America great again.”

The president-elect has long complained about US tax dollars funding European security and has been highly critical about Nato members not spending enough.

Prime Minister’s Questions
Kemi Badenoch called on Sir Keir to back an invitation for Mr Trump to address Parliament and revive talks on a UK-US trade deal (Stefan Rousseau/PA)

He has also repeatedly claimed he would bring the war in Ukraine to an end, although he has not set out how he would achieve this.

Ukraine’s Volodymyr Zelensky was quick to congratulate Mr Trump and said: “I appreciate President Trump’s commitment to the ‘peace through strength’ approach in global affairs. This is exactly the principle that can practically bring just peace in Ukraine closer. I am hopeful that we will put it into action together.

“We rely on continued strong bipartisan support for Ukraine in the United States.”

Nato secretary general Mark Rutte said Mr Trump’s leadership “will again be key to keeping our alliance strong”, adding: “Through Nato, the US has 31 friends and allies who help to advance US interests, multiply American power and keep Americans safe.”

Addressing Mr Trump’s concerns about burden-sharing, he added: “Two-thirds of Allies now spend at least 2% of their GDP (gross domestic product) on defence, and defence spending and production are on an onward trajectory across the alliance.”

Former defence secretary Sir Ben Wallace said the return of Mr Trump should spur European Nato members to commit more to security, with a pledge to spend 3% of GDP.

“Whatever your feelings about the US election are, the best insurance for all our security is to invest in our own defence and security right across Europe,” he said.

Reform UK’s Nigel Farage, a leading supporter of Mr Trump, said the president-elect would be a “genuine radical”.

He told BBC Radio 4’s Today: “What you are going to see from this Trump administration, and I’m guessing that Elon Musk will be the man that is tasked to do it, is there will be a big fightback against the administrative bureaucratic state which is far too big, far too powerful and actually very undemocratic.