How Trump has managed to overshadow the UK’s leadership race

President Donald Trump, whether intentionally or not, is managing to play a key role in the race to become the next U.K. prime minister.

Current Foreign Secretary Jeremy Hunt and his predecessor Boris Johnson are the final two candidates in the race. Their approach to Brexit, future trade deals and the U.K.’s much-vaunted “special relationship” with the U.S. have been at the forefront of public debates between the candidates. Particularly as its EU withdrawal remains uncertain and that has a direct knock-on effect for the U.K.’s future trading relationships with the world.

And how both men would deal with the unignorable figure of Trump looms large too.

Trump’s influence on U.K. politics came to the fore in recent days following the controversy surrounding leaked memos sent by the U.K. ambassador to the U.S. in which he called the U.S. administration “uniquely dysfunctional” and “inept.”

Kim Darroch’s resignation on Wednesday came after Trump publicly lambasted the experienced diplomat, calling him a “very stupid guy” who “had not served the U.K. well,” adding that the U.S. “would no longer deal with him.” He also criticized outgoing Prime Minister Theresa May and her handling of Brexit negotiations.

For the U.K., it’s impossible to ignore that the country will want to remain on best terms with Trump, not just to maintain political ties but economic ones as it seeks a trade deal with the U.S. once it leaves the EU.

Tony Travers, director of the LSE London research center at the London School of Economics, told CNBC Wednesday that Trump is a “big challenge for the U.K. government.”

“At the moment, it happens that the U.S. president is unusual by international standards and that gives British politicians a greater difficulty … to how they deal with him,” he said.

“Both these Conservative leadership candidates have to live with the fact that Donald Trump might be president for three or four years and the trade negotiations that Britain is going to conduct assuming that Brexit actually happens. And it’s against that backdrop that they have to be careful,” Travers said.

If they want the best possible trade deal with the U.S. (as Trump has promised previously) “to get that, you have to be on friendly terms with the leadership of the country concerned,” Travers said.

Political commentators speculated this week that Darroch’s departure was due to pressure from the White House and a lack of public support from Johnson, who is the frontrunner to become the prime minister.

Johnson refused to back Darroch over the Trump remarks during a televised debate Tuesday, saying he didn’t want to politicize Britain’s civil service, which is meant to be apolitical.

Johnson declined to say if he would replace Darroch as ambassador and appeared to signal that the most important issue was maintaining good ties with the U.S., leading his rival Hunt to question how much influence the U.S. had over British political decision-making.

Johnson said Trump had been “dragged into a British political debate … I don’t think that’s the right thing to do … but let’s face it, our relationship with the U.S. is of fantastic importance.” In an interview with Politico published Thursday, Johnson even agreed with Trump’s characterization of May’s Brexit approach as “foolish,” saying “I can’t dissent from that.”

His rival in the leadership race, Hunt, has taken a different stance. He publicly backed Darroch and directly confronted Trump on Twitter on Tuesday telling him he was “disrespectful and wrong” to the prime minister and the U.K.

During the televised leadership debate on Tuesday, Hunt said “who chooses our ambassadors is a matter for the United Kingdom government and the United Kingdom prime minister, and I have made it clear if I am our next prime minister the ambassador in Washington stays because it is our decision.”

The same debate saw a brief outbreak of agreement when both men spoke of Trump’s tax overhaul, however. The right-wing conservatives lauded his cut for business taxes and Hunt noted that America was now growing at twice the rate of the U.K.

“If we grew at 3%, 3.5% we would have an extra £20 billion to spend on tax cuts for people on low incomes … or our precious public services,” Hunt told the audience.

The nature of Theresa May’s departure means that it’s down to Conservative Party members to pick a leader, rather than the general public. The result is due to be revealed around July 23.