Mr Joyce said he would step down on Monday as leader of the Nationals, the junior government partner.

He had previously resisted calls to quit amid intense scrutiny over his ministerial conduct.

The scandal has dominated Australian headlines for more than two weeks.

He described his decision on Friday as a "circuit-breaker" for his family and new partner.

"This current cacophony of issues has to be put aside," he told reporters.

Prime Minister Malcolm Turnbull issued a statement shortly after thanking Mr Joyce for being a "a fierce advocate for rural and regional Australia".

On Monday morning I will step down as the Leader of @The_Nationals and Deputy Prime Minister of Australia. I would like to thank everyone for offering their support to me, especially the people of New England.

Who is Mr Joyce?

Mr Joyce has built a prominent profile during a parliamentary career that began in 2004.

The outspoken politician is perhaps best-known for once threatening to kill Johnny Depp's dogs over a quarantine violation, and for briefly losing his job over his New Zealand dual citizenship last year.

A leading conservative, he represented rural voters as leader of the National party.

Why was he pressured?

Mr Joyce said he faced a "litany of allegations" in the weeks after a newspaper exposed his relationship with Vikki Campion, his former media adviser. He has repeatedly denied breaching ministerial standards.

Political opponents questioned him after two unadvertised jobs within his party were taken up by Ms Campion last year, and over whether he sought a gift of free housing from a businessman.

He also vigorously denied a sexual harassment complaint that was made against him by another woman.

Last week, he sparred publicly with Mr Turnbull after the PM criticised his "shocking error of judgement" and declared that ministers would be banned from having sex with their staff.

Mr Joyce said Mr Turnbull's comments had "caused further harm" but insisted the pair could still work together.

Joyce's authority eroded

Fighting a barrage of bad headlines, Barnaby Joyce knew his position had become untenable.

Sometimes strenuous denials and combative rebuttals just aren't enough to win back the news agenda.

More importantly, they didn't succeed in maintaining the trust and credibility he has enjoyed for most of his career.

Although Mr Joyce is known as a battler who enjoys a big personal vote, support amongst his colleagues had started to ebb away.

And so, rather than face the potential humiliation of a leadership contest, Mr Joyce took matters into his own hands and put himself on the backbench.

Marriage breakdown

Mr Joyce has previously apologised to his estranged wife Natalie Joyce, four daughters, and Ms Campion, for the public manner in which the scandal has played out.

He has described the breakdown of his marriage as one of "the greatest failures of my life", while Mrs Joyce told media the situation was "devastating".

On Friday, Mr Joyce said he hoped his decision would help his family.

"This has got to stop. It's not fair on them," he said.

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