The UK's Ambassador to the United States has sensationally quit after a blistering row with Donald Trump over a leaked memo.
Sir Kim Darroch bowed to pressure today just hours after Boris Johnson - who's set to be Prime Minister in two weeks' time -
The President branded Sir Kim "wacky" and "stupid" after the top diplomat branded his White House "inept" in a leaked memo dating back to 2017.
Theresa May and Foreign Secretary Jeremy Hunt stood by the Ambassador
But Sir Kim said it had become "impossible" to do his job after Trump disinvited him from meetings with his regime.
And MPs today blamed Boris Johnson for "shamefully forcing out" the envoy by refusing to back him in an ITV debate last night.
Friends of Sir Kim said he decided the game was up after watching the Tory leadership contender fail to back him in the TV showdown.
Furious Foreign Office minister Sir Alan Duncan said Mr Johnson was guilty of "contemptible negligence" and had "thrown this fantastic diplomat under the bus to serve his own personal interests".
Mr Duncan told the BBC: "I'm upset and angry. Boris Johnson, a former Foreign Secretary and he hopes to be the future Prime Minister, has basically thrown our top diplomat under the bus.
"And there are a lot of people here in the Commons who are very very angry and feel he has lost so much respect for having done what he's done.
"His disregard for Sir Kim Darroch and his refusal to back him was in my view pretty contemptible, but also not in the interests of the country he's trying to lead."
Sir Kim wrote: "Since the leak of official documents from this Embassy there has been a great deal of speculation surrounding my position and the duration of my remaining term as ambassador.
"I want to put an end to that speculation.
"The current situation is making it impossible for me to carry out my role as I would like.
“Although my posting is not due to end until the end of this year, I believe in the current circumstances the responsible course is to allow the appointment of a new ambassador.
“I am grateful to all those in the UK and the US, who have offered their support during this difficult few days.
"This has brought home to me the depth of friendship and close ties between our two countries. I have been deeply touched.
“I am also grateful to all those with whom I have worked over the last four decades, particularly my team here in the US.
"The professionalism and integrity of the British civil service is the envy of the world. I will leave it full of confidence that its values remain in safe hands.”
Speaking at Prime Minister's Questions today, Theresa May said it was a "matter of great regret" that Sir Kim "felt it necessary to leave his position".
She added "the whole Cabinet rightly gave its full support to Sir Kim", who "has given a lifetime of service to the UK and we owe him an enormous debt of gratitude."
And in a coded rebuke to Boris Johnson she added: "Good government depends on public servants being able to give full and frank advice.
"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."
Labour leader Jeremy Corbyn told the Commons: "I too regret the resignation of Sir Kim Darroch.
"I think the comments made about him are beyond unfair and wrong. I think he has given honourable and good service and he should be thanked for it.
"And I think the whole House should join together in deeply regretting the feeling that he has obviously got that he must resign at this moment."
Head of the Diplomatic Service Sir Simon McDonald said he accepted the resignation with "deep personal regret".
He told Sir Kim: "Over the last few difficult days you have behaved as you have always behaved over a long and distinguished career, with dignity, professionalism and class.
"The Prime Minister, Foreign Secretary and whole of the public service have stood with you: you were the target of a malicious leak; you were simply doing your job."
A Foreign Office insider told the Mirror: This is an outrageous position for an ambassador to find himself in.
"The next Prime Minister publicly throws this country's representative to the wolves to feed the ego of a fickle child in the White House. It's tantamount to telling the civil service that they are totally disposable."
Foreign Secretary Jeremy Hunt said he was "deeply saddened" adding: "I profoundly regret how this episode has led Sir Kim to decide to resign. He deserves to look back upon his career as a servant of Britain with the greatest satisfaction and pride."
It came after a leak of a cache of memos penned by Sir Kim which gave a scathing assessment of the Trump White House.
In one leaked memo from 2017 Sir Kim said: "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."
He also questioned whether the White House "will ever look competent".
The angry President hit back branding the UK's ambassador "wacky" and Theresa May "foolish".
Downing Street previously said Theresa May had "full faith" in Sir Kim Darroch after the extraordinary breach of confidentiality triggered a political firestorm on both sides of the Atlantic.
But in a tweet on Tuesday Donald Trump said: "The wacky Ambassador that the U.K. foisted upon the United States is not someone we are thrilled with, a very stupid guy."
During an ITV leadership debate, campaign frontrunner Mr Johnson defended the US President saying he had been "dragged into a political debate" and refused to say six times if he'd keep the ambassador.
He said: "I have a very good relationship with the White House and I am very proud of the relationship I was able to build up with the United States."
He added: "It is vital that our civil service is not politicised by ministers leaking what they say."
Labour deputy leader Tom Watson tweeted: "This is a personal tragedy for Kim Darroch.
"It is the inevitable result of a leak organised by dark forces who do down our country, and Boris Johnson's failure to stand up for our sovereignty. Always personal ambition before country with Johnson."
Labour MP and former home secretary Yvette Cooper tweeted: "Appalling it has come to this. Kim Darroch is a serious & honourable public servant who was doing his job. British representation across the world should not be decided by hostile security leaks or bullying belligerence from abroad."
Labour MP Ben Bradshaw said on Twitter: "The shameful forcing out of Kim Darroch after Johnson failed to back him shows Johnson as PM would be nothing more than Trump's lap dog.
"What a humiliating prospect for our United Kingdom."
Naomi Smith, chief executive of anti-Brexit group Best For Britain, said: "Boris Johnson should hang his head in shame. He played Judas last night on TV, ready to give up a British diplomat to appease his paymaster Trump."
And fellow Labour MP Bill Esterson tweeted: "The resignation of Kim Darroch, our US ambassador shows that the UK government is happy to let the US President bully them. Contemptible from our government."
But Brexit Party leader Nigel Farage - who previously coveted the job himself - described the resignation of Sir Kim Darroch as "The right decision."
He tweeted: "Time (to) put in a non-Remainer who wants a trade deal with America."
