A police investigation into the leak of memos written by the UK ambassador to the US has been criticised by former chancellor George Osborne for "encroaching on press freedom".
Sir Kim Darroch’s emails, in which he said Donald Trump was inept, were released to the Mail on Sunday last weekend and eventually led to the ambassador’s resignation.
The inquiry by the Metropolitan Police Counter Terrorism Command, which is responsible for investigating allegations of criminal breaches of the Official Secrets Act, was announced in a statement on Friday attributed to assistant commissioner Neil Basu.
Mr Basu said: Given the widely reported consequences of that leak I am satisfied that there has been damage caused to UK international relations, and there would be clear public interest in bringing the person or people responsible to justice.
The investigation will be reviewed at every stage to ensure a proportionate investigation is undertaken.
I would say to the person or people who did this, the impact of what you have done is obvious. However, you are now also responsible for diverting busy detectives from undertaking their core mission.
He asked the person behind the leaks to turn themselves in and avoid wasting detectives’ time, saying: You can stop this now. Turn yourself in at the earliest opportunity, explain yourself and face the consequences.
Mr Basu also warned all publishers not to publish any leaked documents they may have in their possession, but to turn them in to police or the government.
Mr Osborne, now editor of the Evening Standard, appeared to suggest the statement which called for any leaked documents to be returned to the government was written by a junior officer and Mr Basu should distance himself from the comments.
The former chancellor tweeted: If I were the Metropolitan Police Commissioner, and I wanted to maintain my credibility and the credibility of my force, I would quickly distance myself from this very stupid and ill-advised statement from a junior officer who doesn’t appear to understand much about press freedom.
Peter Spiegel, US managing editor of the Financial Times, also reacted to the statement, tweeting: Well, this is rather chilling from a major police force in a western democracy. What are you going to do, Met Police, arrest us?
The leaked memos caused an international row, with the US president responding to the revelation of Sir Kim’s memos by branding the diplomat wacky and a very stupid guy, as well as vowing to no longer deal with him.
Sir Kim’s resignation came shortly after a TV debate between the two Tory leadership contenders, in which Boris Johnson appeared not to give him his full backing, while Jeremy Hunt said he would keep him on.
Whitehall sources told Sky News that Sir Kim decided the game was up following the lack of support from Mr Johnson, who is expected to succeed Theresa May as prime minister later this month.
Foreign Office minister Sir Alan Duncan said an internal Whitehall inquiry had found no evidence the leak was due to computer hacking.
He told MPs the focus was on finding someone within the system who has released illicitly these communications.
Sir Alan, who is supporting Foreign Secretary Mr Hunt in the Conservative leadership race, told Sky News that Mr Johnson had basically thrown [Sir Kim] under the bus.
I think that the conduct of Boris Johnson has discredited him enormously in the eyes of many people in this country, Sir Alan said.
However Mr Johnson has sought to distance himself from speculation that his comments caused Sir Kim to quit, saying I think that unfortunately what I said on that TV debate was misrepresented to Kim.
He told the BBC that he had spoken on the phone to Sir Kim and the former ambassador told him he had not watched the debate himself, but somebody had told him about the comments.
Despite his initial outrage, Mr Trump wished Sir Kim well, having heard the ambassador also said some very good things.
He added: I wish the British ambassador well but they have got to stop their leaking problems there just like they have to stop them in our country.