Barnaby Joyce says he will resign as Australia's deputy prime minister following a politically damaging saga that began with his affair with a former staffer.
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 politics for more than two weeks.
He described his decision on Friday as a "circuit-breaker" for his family and new partner, with whom he is expecting a baby in April.
"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 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.— Barnaby Joyce (@Barnaby_Joyce) February 23, 2018
Why has Mr Joyce's affair dominated headlines?
Rumours of an affair started to spread after Mr Joyce and Vikki Campion, his former media adviser, were photographed together at a bar in Sydney in February 2017.
In April, Mr Joyce's estranged wife Natalie reportedly confronted Ms Campion about the rumours.
In the following months, Mr Joyce was described by his Nationals colleagues as becoming "a mess".
Mr Joyce finally admitted to the affair with Ms Campion earlier this month but initially refused to resign, insisting that "private matters remain private".
In an interview with Australia's Fairfax Media newspaper on Wednesday, the couple called for scrutiny of their relationship to stop, appealing to the media and the public to "move on".
Mr Joyce also said he was concerned and "deeply annoyed" at the thought that their child might be perceived as "somehow less worthy than other children".
He has previously apologised to Natalie, their 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 described the situation as "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.
Why did Joyce come under political pressure?
The revelation of the affair led to questions over whether Mr Joyce had misused his position in parliament to conduct his relationship with Ms Campion.
He said he faced a "litany of allegations" in the weeks after a newspaper exposed the affair.
Political opponents also 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 has repeatedly denied breaching ministerial standards.
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.
The prime minister ordered his deputy, who later accused him of being "inept", to take leave in order to concentrate on his personal life.
Mr Joyce said Mr Turnbull's comments had "caused further harm" but insisted the pair could still work together.
Meanwhile, Mr Joyce also vigorously denied a sexual harassment complaint that was made against him by another woman.
So who is Barnaby 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.
Joyce's authority eroded
Hywel Griffith, BBC News Sydney correspondent
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.