Speaking to reporters at the White House just days before the results of a vote by members of the British Conservative Party will determine the country’s next prime minister, Mr Trump said he had spoken to Mr Johnson a day earlier.

“I like Boris Johnson,” he said, claiming Ms May had done a “poor job” with Brexit. “I think Boris will straighten it out. A lot of people say Johnson is a different kind of guy.”

The president has never hidden his affection for the frontrunner. Earlier this year he said “he’s been very, very nice to me, very supportive”.

As he made his way to Britain for a state visit he told The Sun newspaper: “I think he is a great representative for your country. I am just saying I think he would be a great prime minister. I think he’s got what it takes.”

20 pictures that sum up President Trump's visit Show all 20 1 /20 20 pictures that sum up President Trump's visit 20 pictures that sum up President Trump's visit An awkward greeting As the Queen welcomed Trump to Buckingham Palace, he shared an awkward handshake with her. PA 20 pictures that sum up President Trump's visit "Oi Trump" Essex teenager Ollie Nancarrow mowed this message to Trump in a field near Stansted airport, in order that the president would be forced to see it as he came in to land. BornEco 20 pictures that sum up President Trump's visit A warm welcome Protesters gesture at the helicopter carrying the president as he arrives at Buckingham Palace on the first day of his visit. Getty 20 pictures that sum up President Trump's visit Inspecting the guard After arriving at Buckingham Palace, President Trump inspected an honour guard with Prince Charles. AP 20 pictures that sum up President Trump's visit Khan hits back After the president insulted Sadiq Khan, the London mayor, over Twitter as he landed in Britain, Khan hit back in this video released by Elle. PA 20 pictures that sum up President Trump's visit Mild reception on the Mall The Mall, the road leading to Buckingham Palace, was lacking in pomp as Trump arrived after his visit to Westminster Abbey, only a very small crowd turned out to see the spectacle. Reuters 20 pictures that sum up President Trump's visit Toast with the Queen The president shared a toast with the Queen at the state banquet on his first night in Britain. Reuters 20 pictures that sum up President Trump's visit Creepy kids This picture of Ivanka Trump and husband Jared Kushner, shared to Ivanka's Instagram, was described variously as "terrifying", like "nightmares" and "scarier than the shining." Getty 20 pictures that sum up President Trump's visit Rolling out the red carpet A red carpet was rolled out for the president's arrival to 10 Downing Street. Reuters 20 pictures that sum up President Trump's visit Meeting with May President Trump met with Prime Minister Theresa May on the second day of his visit. They did not speak privately but in a boardroom meeting. Reuters 20 pictures that sum up President Trump's visit Spouses get along First Lady Melania Trump and husband of the prime minister Philip May attended a garden party for the families of Downing Street staff while the two leaders were in their meeting. Getty 20 pictures that sum up President Trump's visit Baby blimp flies again The famous Trump baby blimp made a return in the protests against the president's visit, after first appearing in July last year. EPA 20 pictures that sum up President Trump's visit Crowd gathers A large crowd of protesters gathered in Trafalgar Square in London to protest the president's visit. Notable protesters included a man selling Donald Trump toilet paper and a man dressed as Vladimir Putin controlling a Trump puppet. PA 20 pictures that sum up President Trump's visit Protesters mix and mingle Supporters of the president and protesters of his visit clashed by Parliament Square on the second day of Trump's visit, with some supporters being hit by milkshakes. Reuters 20 pictures that sum up President Trump's visit Toilet Trump A 20ft statue of Trump tweeting while sitting on a golden toilet was placed in Trafalgar Square as protesters gather on the second day of the president's visit. Tom Batchelor / The Independent 20 pictures that sum up President Trump's visit Corbyn speaks In an address to protesters, Labour leader Jeremy Corbyn accused the president of spreading "hatred" and "racism" and expressed disappointment that Sadiq Khan had "been attacked in the way he was." PA 20 pictures that sum up President Trump's visit Churchill hat During his interview with the president on Good Morning Britain, Piers Morgan gave Trump a hat of a style favoured by Winston Churchill, one of Trump's heroes. ITV 20 pictures that sum up President Trump's visit Bus stop baby Activists Special Patrol Group installed this poster in to several bus stops around Portsmouth ahead of the president's arrival for D-Day commemorations PA 20 pictures that sum up President Trump's visit Fly-past with the queen President Trump watched the Red Arrows fly-past with the Queen at an event in Portsmouth to commemorate the 75th anniversary of the D-Day landings AFP/Getty 20 pictures that sum up President Trump's visit Commemoration speech The president gave a speech at an event to commemorate the 75th anniversary of the D-Day landings. Along with Trump, the prime minister and the royal family, French president Emmanuel Macron and 300 Second World War veterans were in attendance. AFP/Getty

Mr Johnson has responded in kind. Speaking in June during a debate in Carlisle, as part of his shown down with Jeremy Hunt to become prime minister, Mr Johnson said the president had “many, many good qualities”.

He claimed Mr Trump had claimed kick start the US economy. “We should pay tribute to that,” he said.

Mr Trump has often criticised Ms May, in particular for the way she sough to secure Brexit, claiming she had ignored his advice which was to walk away from negotiations without a deal if required.

This month, after details of a classified cable were leaked revealing British diplomat Sir Kim Darroch had said the president oversaw a chaotic administration, Mr Trump attacked both the ambassador and the prime minister on Twitter.

Donald Trump claims he tried to stop 'send her back' chants by 'speaking very quickly'

“I have been very critical about the way the UK and prime minister Theresa May handled Brexit. What a mess she and her representatives have created. I told her how it should be done, but she decided to go another way,” he wrote.

“I do not know the ambassador, but he is not liked or well thought of within the US. We will no longer deal with him.”

He added: “The good news for the wonderful United Kingdom is that they will soon have a new prime minister. While I thoroughly enjoyed the magnificent state visit last month, it was the Queen who I was most impressed with.”