BORIS Johnson has fuelled the controversy over Donald Trump’s unexpected decision to pull out of a visit to the UK by claiming Jeremy Corbyn and Sadiq Khan, Labour’s London Mayor, were putting the UK-US Special Relationship “at risk”.

Suggestions have been made that the US President pulled out of his visit to open the new American embassy in London’s Nine Elms near Vauxhall next month because of the prospect of mass protests, raising doubts that the planned four-day state visit will ever go ahead.

After Mr Trump took to Twitter at 4.57am on Friday to confirm his visit cancellation, Mr Khan welcomed the news saying the President had “got the message from the many Londoners who love and admire America and Americans but find his policies and actions the polar opposite of our city's values of inclusion, diversity and tolerance”.

He noted how Mr Trump would have been met by “mass peaceful protests”.

But the Foreign Secretary took to Twitter to condemn Mr Khan and his party leader, saying: "The US is the biggest single investor in the UK yet Khan & Corbyn seem determined to put this crucial relationship at risk. We will not allow US-UK relations to be endangered by some puffed-up, pompous popinjay in City Hall."

Downing Street was unable to say whether Mr Johnson was speaking for the Government, stressing how it was “not aware of the circumstances of the tweet”.

Asked if Theresa May felt Mr Khan’s comments damaged the Special Relationship, her deputy spokesman said: “No. The US and UK are strong, resilient partners and allies; we do more together than any other two countries in the world.”

On Friday, as the President was mocked on Twitter his waxwork drew public attention as it was placed outside the new embassy by Madame Tussauds.

In his tweet Mr Trump said: "Reason I cancelled my trip to London is that I am not a big fan of the Obama Administration having sold perhaps the best located and finest embassy in London for "peanuts," only to build a new one in an off location for 1.2 billion dollars.

"Bad deal. Wanted me to cut ribbon-NO!"

The deal for the new embassy was struck in 2008 by the administration of George W Bush before Mr Obama came to office.

Asked if the PM was still confident the Trump state visit would go ahead after the President cancelled his February working visit, Mrs May’s deputy spokesman said: “The US is one of our most valued allies. The invitation has been extended and accepted. No date has been confirmed.”

Asked if it was a discourtesy to the Queen for Mr Trump to keep putting off the state visit, he replied: “An invitation has been extended and accepted and we will set out details in due course.”

Meanwhile, there was some criticism of Mr Trump describing the new location of the US embassy as “off-location”; its current home is in the heart of the West End in Grosvenor Square and is being moved to improve security.

Ravi Govindia, leader of Wandsworth Council, said if the south-west London area had been off-location yesterday, "it is certainly centre-stage today".

Just south of the River Thames, the cube-shaped embassy building is in sight of Westminster and part of a £15 billion, 561-acre regeneration project set to transform one of the South Bank's last remaining industrial stretches. It will include 20,000 new homes and 25,000 permanent jobs. Apple is to move its headquarters there.

But, according to Aydin Dikerdem, a Labour councillor for Queenstown, Mr Trump would not be welcome there.

"We all know why he cancelled this visit. He cancelled this visit because he knew there would be mass demonstrations if he dared to come to the opening. He is not welcome in London and he certainly isn't welcome in Queenstown," he said.