Former Coalition minister George Brandis has thrown his support behind Kevin Rudd, even as conservative firebrands call for the Washington ambassador’s resignation.

Brandis, a former ambassador to the UK, took aim at his one-time political colleagues as the row over Rudd’s tenure in the US – sparked by a spray from US presidential candidate Donald Trump – took a wilder turn on Thursday.

“I think this has been rather overinterpreted. Donald Trump is infamous for making rather wild and off-the-cuff claims that don’t in the end amount to very much, so it’s obviously something that the government should keep an eye on. But I wouldn’t overinterpret it,” Brandis told ABC radio.

Trump roasted the former Australian PM in an interview aired by GB News on Thursday, after Brexit campaigner-turned-broadcaster Nigel Farage raised Rudd’s criticism of Trump in an interview at the behest of Sky News Australia.

Trump lashed out, calling Rudd “a little bit nasty” and warning that he would “not be there for long”.

The comments sparked a political firestorm in Australia, as opposition politicians warned a hostile relationship between the presidential hopeful and the Australian ambassador could put pressure on diplomatic relations if Trump is re-elected later this year.

Also on Thursday, Farage poured more fuel on the fire, saying Australia must “pull Kevin Rudd out”.

For Australia’s trilateral security alliance with the US and Britain to flourish, the Commonwealth needed an ambassador that could talk to the president, Farage said.

While Trump has a history of working with high-profile figures after publicly bullying them, Farage said this was unlikely to apply to Rudd.

“There’s more chance of him having tea with Kim Jong-Un,” he told Nine’s Today.

“That relationship clearly is not going to work.

“A Trump victory [means] maybe Mr Rudd’s home for Christmas.”

But Brandis urged caution on Trump – and Farage.

“I know Nigel Farage – he’s a charming charlatan who’s building a reputation as a broadcaster in the United States, obviously,” he said.

“He is interested in attracting as much importance to his interviews as possible, but I don’t think Nigel Farage has views on this matter.”

Brandis said it was important that Australia’s senior diplomatic representatives – whether career diplomats or political appointees – had bipartisan support.

“If they don’t, it diminishes their authority, and therefore diminishes their influence in the country to which they’re accredited,” he said.

“That’s plainly not in Australia’s national interest. Now, when the appointment of Dr Rudd was announced in December of the year before last, it wasn’t criticised on a party basis in Australia.”

Brandis’s comments are out of step with his former Coalition colleagues, who have criticised Rudd after the Trump comments. On Thursday, opposition frontbencher Barnaby Joyce said Rudd was “cooked” if Trump won November’s presidential election.

“Rudd’s cooked,” he told Nine.

“Might as well drag him back, send him to another country, send him over to France or, I don’t know, The Hague or make him deputy secretary of the United Nations. I don’t know, do something else with him. There’s lots of lots of other jobs, lots of wonderful Pacific islands. They need Kevin.”

Before Rudd’s appointment to Washington, he decried Trump as a “traitor to the west” and “the most destructive president in history” who “drags America and democracy through the mud”.

Despite this week’s uproar, he maintains the backing of the Albanese government, which appointed him.

“We’re very confident that whatever happens in November, he’ll be able to work with all US administrations,” Health Minister Mark Butler told Today.

“Kevin Rudd is very widely respected right across the aisle. He’s bringing his usual work ethic to networking in America, as he did so notoriously here in Australia.”

Former chief of the US National Security Agency Michael Rogers, who has worked with Rudd, said he had a lot of respect for him but noted any decisions on his future were for Australia, not the US.

“I would urge everyone to step back,” he told ABC radio.

Rudd is not the only Australian political figure to decry the Republican nominee.

In 2020, former Liberal defence industry minister Christopher Pyne wrote that Trump “does not have the emotional equipment to be president”, while in 2015 ex-treasurer Josh Frydenberg called him a “dropkick”.

-with AAP