Officials say Britain is trying to find out who leaked emails sent by Kim Darroch, Britain's ambassador in US, who branded President Trump's administration as "dysfunctional" and "inept".
The British government was hunting on Monday for the source of a leak of diplomatic cables from Britain's ambassador in Washington that branded President Donald Trump's administration "dysfunctional" and "inept."
"I've seen nothing to suggest hostile state actors were involved," said Prime Minister Theresa May's spokesman, James Slack.
The enquiry is being led by civil servants in the Cabinet Office, and Slack said police would only be called in "if evidence of criminality is found."
Embarrassed and alarmed
British officials are embarrassed by the publication of Kim Darroch's unflattering assessment — but more alarmed that sensitive confidential information has been leaked, possibly for political ends.
The leaked cables were intended for senior UK ministers and civil servants, and officials believe the mole will be found among British politicians or officials, rather than overseas.
It's possible the leaker could be charged with breaching the Official Secrets Act, which bars the unauthorised disclosure of classified material.
Slack said May had "full faith" in Darroch, a long-serving diplomat, although she didn't agree with his characterisation of the Trump administration.
He said ambassadors were hired to provide "honest, unvarnished assessments" of politics in the countries where they served, which didn't necessarily reflect the views of the British government.
Content of cables
In the leaked cables — published in the Mail on Sunday newspaper — Darroch called the Trump administration's policy toward Iran "incoherent," said Trump might be indebted to "dodgy Russians" and raised doubts about whether the White House "will ever look competent."
"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," one missive said.
The cables cover a period from 2017 to recent weeks. Darroch has served as Britain's envoy to Washington since 2016.
After the cables were published, Trump said the ambassador "has not served the UK well, I can tell you that."
"We are not big fans of that man," Trump said.
The leak is an embarrassment for outgoing prime minister May, who has sometimes clashed with Trump and could make things difficult for Darroch, who is accused by some Brexit-backing UK politicians of a lack of enthusiasm for Britain's departure from the European Union.
The journalist who reported the leak, Isabel Oakeshott, is a strong supporter of Brexit and ally of Brexit Party leader Nigel Farage, Britain's leading champion of Trump.
Trump said in 2016 that Farage would "do a great job" as ambassador to Washington.
Farage brushed off that idea on Monday, saying "I'm not a diplomat, and I think that's quite an understatement."
But Farage said Darroch's comments were "pretty irresponsible."
British Foreign Secretary Jeremy Hunt said on Monday that the ability to communicate frankly was "fundamental" to diplomacy.
International Trade Secretary Liam Fox, who is meeting US officials in Washington, called the leak "malicious."
"I think it is unconscionable that any professional person in either politics of the civil service can behave in this way," he said.
Fox, who is due to meet Trump's daughter Ivanka, told the BBC that he would apologise for the fact that standards of "either our civil service or elements of our political class" had "lapsed in a most extraordinary and unacceptable way."