Prime Minister Theresa May, who had given Darroch her full support, told Parliament after the resignation was announced that she had spoken to Darroch, who was due to leave his post anyway at the end of the year.
"If that's the case I think it's clear that Boris Johnson is effectively behaving as Donald Trump's patsy and he's doing that clearly because he is banking on a sweetheart trade deal and is putting himself in hock to the USA president", the spokesman told reporters. The respected diplomat's move has caused Britain's relations with the USA presidency to sink to its lowest levels in decades. May expressed "great regret" at Darroch's departure. "Like I've said, sometimes a great story is just that; not some kind of global conspiracy".
"Somebody has, for whatever malicious reasons, sought to either damage the UK-US relationship or indeed Sir Kim personally", British trade minister Liam Fox told reporters.
On Tuesday, Hunt condemned Trump's outbursts as "disrespectful and wrong".
Darroch has received support from across the British political spectrum.
Memos from Kim Darroch describing the Trump administration as inept were leaked to a British newspaper, infuriating the United States president, who launched a Twitter attack on both the envoy and outgoing prime minister Theresa May, who had given Darroch her full support.
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He said he regretted how an "outrageous leak caused this". Darroch often addressed the attendees at such gatherings, making sure to single out high-level administration officials. This has brought home to me the depth of friendship and close ties between our two countries.
It's unclear whether May will have time to name a replacement before she leaves office later this month. The insults had been in response to the publication last Sunday of a collection of confidential e-mails Sir Kim had sent to government officials in London in which he described the Trump White House as "clumsy and inept".
"It is shameful that Kim Darroch has effectively been forced out for doing the job that diplomats are appointed to do", Scottish First Minister Nicola Sturgeon tweeted.
Appointing ambassadors usually involves a formal civil service process with advertisements, applications and interviews, though Simon McDonald, head of Britain's diplomatic service, said the post of ambassador to the U.S. wasn't always chosen that way.
Foreign Office minister Alan Duncan went further, accusing Johnson of having "thrown our top diplomat under a bus" for his own personal interests. "Boris Johnson's failure last night to stand up for him - and stand up to the behavior of Donald Trump - spoke volumes".
But Trump supporter and Brexit Party leader Nigel Farage described the resignation as, "the right decision".
"I want all our public servants to have the confidence to be able to do that and I hope the House will reflect on the importance of defending our values and principles, particularly when they are under pressure".