Newly accredited US Ambassador Richard Grenell (ODD ANDERSEN/AFP/Getty)

The only openly gay ambassador appointed by Donald Trump is facing calls to be sacked – after he said he would work to “empower” conservatives across Europe.

Under President Obama, the United States took a stand for LGBT rights by appointing a string of out-and-proud ambassadors around the world, including in countries where homosexuality is still taboo – but the political appointees lost their jobs under Trump.

The current leader has appointed just one openly gay ambassador, the US Ambassador to Germany Richard Grenell.

But Grenell’s position is in peril after he gave a controversial interview to far-right outlet Breitbart vowing to “empower” Europe’s resurgent ultra-conservative movements.

He said: “Many migrants have been allowed to come in, that was the policy of Chancellor Merkel.

“There are a lot of conservatives throughout Europe who have contacted me to say they are feeling there is a resurgence going on.

“I absolutely want to empower other conservatives throughout Europe, other leaders. I think there is a groundswell of conservative policies that are taking hold because of the failed policies of the left.

“There’s no question about that and it’s an exciting time for me. I look across the landscape and we’ve got a lot of work to do but I think the election of Donald Trump has empowered individuals and people to say that they can’t just allow the political class to determine before an election takes place, who’s going to win and who should run.”

The comments, an apparent breach of diplomatic protocol on political neutrality, caused the German Foreign Ministry to ask him to clarify the remarks.

Senator Jeanne Shaheen, a member of the Foreign Relations Committee, said: “An ambassador’s most critical responsibility is to advance our national interests by developing relationships and trust with their host country.

“They should not meddle in local or regional politics by backing political parties, candidates or causes.

“The United States does not accept foreign meddling in our elections, and we shouldn’t have an ambassador attempting to intrude in another country’s political affairs.”

US Senator Chris Murphy added: “When I raised concerns to Grenell about politicising this post [in the past], he personally assured me that once he became Ambassador he would stay out of politics.

“This interview is awful – Ambassadors aren’t supposed to ’empower’ any political party overseas.”

Grenell previously served as a spokesman for Mitt Romney during his US Presidential bid.

His nomination as Ambassador faced opposition from Democrats in the Senate for making derogatory remarks about women on Twitter and criticising the appearances of Hillary Clinton and US ambassador to the Holy See, Callista Gingrich.

He apologised for the comments and deleted them from the social media platform.