One of Australia's most combative politicians, Barnaby Joyce, is set to resign as deputy prime minister and leader of the National Party, the junior partner in the centre-right government.

The catalyst for his resignation was the father-of-four's extra-marital affair with a former media adviser, who is pregnant with his child.

While Mr Joyce, 50, is walking away from two high-profile leadership roles, he intends to stay on as a federal MP representing the seat of New England in New South Wales.

Once a keen rugby player, the departing deputy PM, known for his trademark rabbit-fur Akubra hat, has always relished cut and thrust of competition. During his playing days, he suffered a distended spleen, fractured ribs and had his face patched up with 28 stitches.

His roots are planted firmly in the Australian bush; he was a farm worker, studied accountancy at a regional university in the late 1980s, and became a rural banker before running his own business in Queensland.

"He oozed an air of authenticity that the well-polished politicians in Canberra, like indeed our prime minister, did not have," explained Dr Vincent O'Donnell, a media and communications expert from Melbourne's RMIT University.

"[That] appeals to rural and regional folk who don't really trust Canberra with the degree that perhaps some city people do."

Mr Joyce is from a large farming family that lived on a cattle and sheep property near the village of Woolbrook in his current seat.

He was elected to the Senate representing Queensland in 2004, and almost a decade of service followed before he resigned in 2013.

Ambitious and a fierce advocate of country people, he was determined to enter the more high-profile stage of Australian politics, the House of Representatives, and won in New England in 2013 and again in 2016.

His resignation from the leadership positions is not the only recent jolt to his political career.

Last year, Mr Joyce was ensnared in Canberra's dual nationality saga, and was forced out of parliament after it was revealed he had breached the constitution by not renouncing his New Zealand citizenship - which he had inherited through his father.

Such was his popularity, Mr Joyce was returned in a landslide by-election victory last December.

He has held various ministerial portfolios, including agriculture, infrastructure, transport, and resources and northern Australia. But it was a spat with a Hollywood star that brought the former accountant into the glare of the international media.

In 2015, US actors Johnny Depp and Amber Heard were caught illegally smuggling their dogs, Pistol and Boo, into Australia. Mr Joyce famously threatened to have the fugitive pooches put down.

"It doesn't matter if Johnny Depp has been awarded sexiest man alive twice, it's time Boo and Pistol bugger off home... or we're going to have to euthanise them," he said.

Depp responded, telling American late-night television that Mr Joyce looked like he was "inbred with a tomato". The politician appeared to thrive on the verbal sparring.

As one of Canberra's most knock-about politicians, Mr Joyce has often been in the headlines. His popularity gave him political power. He cultivated a profile as a champion of the bush. What could go wrong?

But as the scandal arising from his affair began to intensify, he increasingly looked doomed.

Infuriated by Prime Minister Malcolm Turnbull's stinging criticism of his "shocking error of judgment", Mr Joyce only dug in further. Ultimately, he could not withstand pressure that seemed to mount daily.

The saga has raised questions about the unity of the coalition headed by Mr Turnbull, who is leader of the Liberal Party.

Prof Rodney Smith, from the department of government at the University of Sydney, said Friday's resignation was "likely both to weaken the National Party but will also make National Party MPs a little bit resentful because of the fact that the prime minister did come out so openly and criticise Joyce and tell him to consider his position".

So will the man in the broad-rimmed hat see out his political journey as a backbench MP? Maybe not.

"I wouldn't rule out a comeback particularly if down the track, say, after the next election the National Party doesn't do so well or the coalition goes into opposition, then he is an obvious candidate for a comeback," Prof Smith told the BBC

"His days aren't necessarily over."