Britain’s contest for prime minister roiled by Trump’s bare-knuckled attack on envoy to Washington

President Trump’s full-throated attack on Britain’s ambassador to Washington is roiling the race for prime minister, putting the Trump-friendly front-runner in an awkward spot.

The extraordinary diplomatic spat between Britain and the United States, a historically close alliance, has erupted just two weeks before a party leadership vote determines who will replace Prime Minister Theresa May.

Trump has all but demanded the removal of Britain’s envoy to the United States, Kim Darroch, after a British tabloid’s publication of leaked diplomatic cables in which the ambassador depicted the U.S. president and his administration as “inept” and “dysfunctional.”

Since the report’s publication in the Mail on Sunday, Trump has responded with a steadily escalating show of displeasure. After initially saying merely that he wasn’t “a fan” of the ambassador, he declared Monday that “we will no longer deal with” Darroch.

Then on Tuesday, the presidential commentary took a sharply personal turn, with Trump excoriating the envoy on Twitter as “wacky” and “a very stupid guy,” while launching a broader attack on May’s “foolish” handling of Brexit, her country’s planned departure from the European Union.

May, who will remain in office until her successor is determined in a party vote that ends July 21, has strongly affirmed her support for the 65-year-old diplomat, even while expressing chagrin over the leak of what were supposed to have been closely held communiques. The ambassador, she said, was simply doing his job.

That means it will most likely be the next prime minister who decides Darroch’s fate. Trump has warmly praised the leading candidate, former Foreign Secretary Boris Johnson, who at a debate Tuesday night with rival Jeremy Hunt was reluctant to offer any criticism.

“I don’t think that was necessarily the right thing for him to do,” he finally said of Trump’s attacks on both the ambassador and May. The U.S. president, Johnson said, had been “dragged into a British political debate.”

Hunt, the current foreign secretary, was far more forthright. Earlier Tuesday, when Trump began hurling personal insults, he suggested the U.S. president had crossed a diplomatic line.

“Friends speak frankly so I will,” Hunt wrote in a pair of tweets addressing Trump. “Allies need to treat each other with respect…and if I become PM our Ambassador stays.”

Critics warned that early removal of Darroch — who is due to leave his post by year’s end anyway — would amount to buckling to pressure from a U.S. leader who has already subjected the two countries’ “special relationship” to considerable stress.

Tom Watson, deputy head of the opposition Labor Party, wrote on Twitter that abruptly yanking the ambassador “would be nothing short of a humiliating capitulation to bullying” by Trump.

Trump’s near-constant stream of tweeted commentary and advice — not only on Brexit but also on matters such as the British government’s response to domestic terrorist attacks and the fitness of Sadiq Khan, the mayor of London — has represented a sharp break from long-standing U.S. presidential practice of avoiding overt entanglement in allies’ domestic affairs.

Last month, Trump was feted during a pomp-filled state visit to Britain, dining with Queen Elizabeth II and hobnobbing with other members of the royal family. But polls consistently show him to be deeply unpopular among Britons.

With Britain due to leave the European Union on Oct. 31 — and the looming possibility of a chaotic no-deal exit — one of the new prime minister’s chief preoccupations will be trying to pave the way for a favorable trade arrangement with the United States. And the implicit argument being made by some politicians is that if that means appeasing Trump, so be it.

But the options are unappealing even for some Conservative politicians who raised little objection when Trump has stepped in with unsolicited advice on how to expedite Brexit. He once urged May, for example, to sue the EU.

Britain is proud of its diplomatic corps, which is widely regarded as rigorously professional. And the idea that an ambassador with a distinguished record should be punished for criticizing Trump, in communiques intended only for a small, select audience, is clearly sticking in the craw of some.

Darroch is Sir Kim, having been knighted in 2008 for his service to country, and is admired by many for his rise from a humble upbringing in housing projects to the pinnacle of his profession.

William Hague, who like Johnson and Hunt has served as foreign secretary under a Conservative government, suggested Tuesday that Trump may simply not understand that it is normal for an envoy to combine public politesse with frankness in private reports. The new British leader, he told the BBC, “will need to explain that you can’t change an ambassador at the demand of a host country.”

At the same time, there is recognition in official circles that a genuine freeze-out by Trump, particularly if extended to matters such as intelligence-sharing and contacts with senior White House aides, might make it impossible for Darroch to serve as an effective interlocutor.

The State Department said Tuesday that it had not received any instructions from the White House to cut off dealings with the British Embassy. Spokeswoman Morgan Ortagus said the “special relationship” between the U.S. and Britain is “bigger than any government.”

Trump’s domestic detractors say his angry response to the leaked cables validates the envoy’s depiction of him as thin-skinned.

“Oh, yes, and this completely rebuts Ambassador Darroch’s observation that Trump is ‘insecure,’” said a sarcastic tweet from George Conway, a prominent Trump critic who is the husband of senior White House aide Kellyanne Conway.

However it ends, the episode is a reminder of Trump’s penchant for conducting diplomacy in purely personal terms, with little input from his State Department, intelligence professionals or other experts. Some observers warned of long-term consequences to important alliances.

“When Trump just tweets insults at our allies, America moves on,” tweeted Brian Klaas, a Britain-based academic who studies authoritarian governments. “But it does damage, and years of Trump’s ally bashing is taking a toll on relations.”

Special correspondent Boyle reported from London and Times staff writer King from Washington. Staff writer Tracy Wilkinson in Washington contributed to this report.

laura.king@latimes.com

@laurakingLAT