Joe Biden says Theresa May called him to voice concerns about Trump

Joe Biden has claimed Theresa May phoned him to voice concerns over Donald Trump’s leadership – a claim likely to embarrass the prime minister, who has attempted to forge a close relationship with the Republican president.

Mr Biden, who is leading opinion polls for the 2020 Democratic nomination, revealed the alleged phone call with Ms May - whom he briefly confused with Margaret Thatcher - during a fundraiser on Saturday.

“Margaret Thatcher, um, excuse me, Margaret Thatcher — Freudian slip,” Mr Biden said to laughter from top donors to his campaign, according to a campaign pool report. “But I knew her too.”

After a pause, he added: “The prime minister of Great Britain Theresa May.”

Mr Biden said "at least 14 world leaders" had called him during Mr Trump's tenure expressing unease, including Ms May, who asked him directly for reassurance that the US and the UK "still have a special relationship".

Downing Street told The Independent it has no record of such a call.

Mr Biden’s claim comes just weeks before Mr Trump is due to meet Ms May during a state visit to the UK.

Despite regular attacks aimed at both the UK and Ms May personally by the US president - on subjects from terrorism to her handling of Brexit - the prime minister has remained reluctant to criticise Mr Trump since he took office in 2017.

The government is keen to sign a trade deal with the US once Britain has left the EU, and keeping Mr Trump onside is seen by some as crucial to Britain’s prospects of striking such an agreement.

But Mr Biden, who hopes to become the oldest US president in history in 2020, said America under Mr Trump was “about to squander alliances" built over generations.

He noted he had "spent my entire adult life" in foreign affairs, first with 36 years in the Senate then eight years as Barack Obama's vice-president.