Boris Johnson has refused to say he would keep Sir Kim Darroch as Britain’s ambassador to the US if he became prime minister.

During a live television debate between the two Tory candidates to become the next prime minister, the former foreign secretary initially evaded the question and refused to commit himself on Sir Kim’s fate, but when pressed said he wouldn’t be “presumptuous”.

Jeremy Hunt, by contrast, said he would keep Sir Kim in place until he retires at the end of the year.

“Who chooses our ambassadors is a matter for the United Kingdom government and the United Kingdom prime minister so I’ve made clear that if I am our next prime minister, the ambassador in Washington stays,” Mr Hunt said.

Mr Johnson tried to put the focus on his rival by questioning whether he would keep the ambassador on beyond Sir Kim’s planned retirement date.

Biggest lies told by Boris Johnson Show all 5 1 /5 Biggest lies told by Boris Johnson Biggest lies told by Boris Johnson Made-up quote for The Times Johnson was sacked from The Times newspaper in the late 1980s after he fabricated a quote from his godfather, the historian Colin Lucas, for a front-page article about the discovery of Edward II’s Rose Palace. “The trouble was that somewhere in my copy I managed to attribute to Colin the view that Edward II and Piers Gaveston would have been cavorting together in the Rose Palace,” he claimed. Alas, Gaveston was executed 13 years before the palace was built. “It was very nasty,” Mr Johnson added, before attempting to downplay it as nothing more than a schoolboy blunder. PA Biggest lies told by Boris Johnson Sacked from cabinet over cheating lie Michael Howard gave Boris Johnson two new jobs after becoming leader of the Conservatives in 2003 – party vice-chairman and shadow arts minister. He was sacked from both positions in November 2004 after assuring Mr Howard that tabloid reports of his affair with Spectator columnist Petronella Wyatt were false and an “inverted pyramid of piffle”. When the story was found to be true, he refused to resign. PA Biggest lies told by Boris Johnson Broken promise to boss In 1999 Johnson was offered editorship of The Spectator by owner Conrad Black on the condition that he would not stand as an MP while in the post. In 2001 he stood - and was elected - MP for Henley, though Black did allow him to continue as editor despite calling "ineffably duplicitous" PA Biggest lies told by Boris Johnson Misrepresenting the people of Liverpool As editor of The Spectator, he was forced to apologise for an article in the magazine which blamed drunken Liverpool fans for the 1989 Hillsborough disaster and suggested that the people of the city were wallowing in their victim status. “Anyone, journalist or politician, should say sorry to the people of Liverpool – as I do – for misrepresenting what happened at Hillsborough,” he said. PA Biggest lies told by Boris Johnson ‘I didn’t say anything about Turkey’ Johnson claimed in January, that he did not mention Turkey during the EU referendum campaign. In fact, he co-signed a letter stating that “the only way to avoid having common borders with Turkey is to vote Leave and take back control”. The Vote Leave campaign also produced a poster reading: “Turkey (population 76 million) is joining the EU”

He condemned the person who leaked the memos from Sir Kim, and conceded Donald Trump’s criticism of Sir Kim was “not necessarily the right thing to do”.

“I’m not going to be so presumptuous as to – what I will say is that I and I alone takes important and politically sensitive jobs,” Mr Johnson said.

Donald Trump has insisted he will no longer deal with the UK ambassador after leaked diplomatic cables revealed him calling the US administration “dysfunctional” and “inept”.

In one scathing assessment, Sir Kim wrote: “We don’t really believe this administration is going to become substantially more normal; less dysfunctional; less unpredictable; less faction riven; less diplomatically clumsy and inept.”

The Foreign Office is investigating who is behind the leak.

The US president said Sir Kim was “not liked or well thought of” within the US.

There have been suspicions Mr Johnson was interested in making Nigel Farage, who has called for Sir Kim’s sacking, the UK’s ambassador.

When asked on BBC Radio 4 whether he would take the job, the Brexit Party leader said: “I don’t think I am the right man for that job.”