The US president clearly wants him gone, but diplomats haven’t always seen eye to eye with the White House

The worst fears of Downing Street and the Foreign Office have been realised by the latest tweet from Donald Trump declaring that his administration will no longer deal with the British ambassador to Washington, Sir Kim Darroch.

The reference to “we” in Trump’s tweet suggests the US president intends to send a missive to all the various agencies of government that contact with Sir Kim is being broken off until he leaves his post.

Jeremy Hunt, the UK foreign secretary, had tried to de-escalate the crisis by saying the UK government did not agree with what Darroch had written about the chaos in the Trump administration, but he nevertheless defended his ambassador’s right to give his personal advice in private.

It was a delicate balancing act of trying to preserve the special relationship, and at the same time the underlying requirement of the diplomatic profession to tell the truth privately.

Clearly Hunt’s formula has not worked, and it now seems for practical purposes that Darroch, due to leave his post anyway this winter, is becoming a diminishing asset. Trump certainly has mood swings, and can decide to change his mind from one day to the next, but he is also thin-skinned, as Darroch testified in his leaked memos. And once the president takes against a perceived critic, the grudge can be irreversible.

Nevertheless, there will be those in the Foreign Office who believe Darroch should not be punished for writing in private what most members of the White House staff would agree to be virtually a truism.

They also regard the leak and the suspiciously coordinated attack on the neutrality of the civil service by Nigel Farage as a moment to dig in and defend the integrity of their profession. The populists’ long, destructive march through the institutions was never likely to stop at Whitehall, and now they know the wrecking ball has reached the Foreign Office.

The mood in the department will turn on events in the next few weeks, providing an early test for a likely Johnson premiership on how he sees his relations with the civil service, with America and with the domestic Brexit movement.

The immediate issue that arises for the outgoing prime minister, Theresa May, and the Foreign Office’s permanent undersecretary of state, Sir Simon McDonald, is whether Sir Kim Darroch, his relations with Trump irreparably damaged by the exposure of the unflattering telegrams, can realistically see out his expected tenure. Trump has expressed his displeasure, and would clearly like Darroch to pack his bags.

But it is argued there are many branches to the Trump administration, as well as the near-seamless intelligence relationship, and if the doors to the White House are slammed shut in Darroch’s face, he can remain both an influencer and a valuable interlocutor for either London or Washington. It was claimed that many Republicans understand it is the task of an ambassador to send his version of the unvarnished truth.

Some of the UK’s best ambassadors have not sympathised with the occupants of the White House. That did not stop them being acute observers of the scene. Darroch’s early departure might seem pragmatic, but it would also be a victory for the leakers, and reflect a misunderstanding of a diplomat’s role.

The second, more important issue for the Foreign Office will be the choice that the new prime minister makes about Darroch’s successor, a decision that was always going to have to be made in the autumn.

Tom Fletcher, a former UK ambassador to Lebanon who is close to the current diplomatic corps, reflected a determination to defend Darroch, tweeting: “Surely in UK and US interests interests to contain damage that leaker has done. Serious leaders know diplomats have duty to report candidly. For a president to personally attack an ambassador of an ally in this way is deplorable. Ambassador can’t defend himself, but ministers should.”

A political appointment from outside the civil service in the current context might be seen as an admission that Farage is right, and that there is no one within the Foreign Office capable of being sufficiently enthusiastic about the possibilities of Brexit to seize the chance provided to build an even stronger relationship with Trump.

Play Video 0:33 Donald Trump: 'We're not big fans' of UK ambassador to US – video

But there will be deep resistance inside the Foreign Office to an outsider. The introduction of a Brexiter businessman, Nigel Farage’s proposition, would be an admission that the Foreign Office collectively cannot bend to its political masters’ bidding. It would be a humiliation, and a public statement of the new administration’s loss of trust in its advisers – a diplomatic Rolls Royce condemned as an untrustworthy banger.

The Foreign Office would have reason to feel doubly aggrieved, since Brexit was largely taken out of its hands. If there have been difficulties in extricating the UK from Brussels or striking new trade deals, the recusants are more likely to lie in the Brexit and trade departments. Richard Moore, political director at the Foreign Office sinceApril 2018, probably spends half his time not on Brexit, but Iran.

McDonald, no great enthusiast for Johnson’s time as foreign secretary, likely to leave his post soon after a tumultuous five years, will find many diplomats encouraging him to make a last stand in defence of the integrity of their profession. Those that claim Darroch has not made the best of the opportunities to get close to the Trump administration are really suggesting May should have adopted a different policy on climate change, Iran, Libya and multilateralism. As McDonald himself said, it has been striking how many times on big foreign policy questions May sided with the French rather than Uncle Sam.

Liam Fox defends UK ambassador to US in row over leaked memos Read more

Yet it is not unprecedented for the post in Washington to be given to a political appointee. Lord Owen unceremoniously sacked Peter Ramsbotham in 1977, appointing in his place Peter Jay, a young financial journalist and son-in-law of the former prime minister James Callaghan. It was generally acknowledged afterwards to have been a mistake.

Hunt also recently won an internal Foreign Office battle to open up more diplomatic posts to outsiders. Adverts for these posts have just been circulated, even if there was no expectation that major ambassadorships would be appointed outside the professional ranks.

Play Video 0:57 Nigel Farage says UK ambassador should be sacked – video

Nigel Farage modestly ruled himself out as the next US ambassador, but suggested he could work as adviser to the UK government on intelligence, security and trade relations, a job description that would leave the role of the ambassador somewhat circumscribed.

But Brexiters clearly feel that the civil service is awash with unreconciled Europhiles that have mounted a rearguard resistance to Brexit, so making the UK’s exit from the EU less of a triumph than it should have been. They point to the pro-European leanings of retired diplomats, the visceral essays by Sir Ivan Rogers, the former UK ambassador to the EU, and to the warnings issued by the civil servants responsible for no-deal Brexit planning.

Yet as Lord Maude, the Conservative politician who has grappled most over the past decade with the issue of civil service neutrality, would often affirm, the best civil servant is one who challenges a minister, loses the argument, then carries out the minister’s instructions. The worst civil servant is the one who pretends to agree with a minister, then carries on with their own agenda regardless of the minister’s instructions. Challenge, or a commitment to analysis, does not equate to resistance.