Barnaby Joyce quits as Deputy Prime Minister

Barnaby Joyce has bowed to the inevitable and finally resigned, quitting the Deputy Prime Ministership and Malcolm Turnbull's frontbench more than two weeks after news that he and his former staffer-turned-partner Vikki Campion are expecting a baby boy.

The resignation comes after rising public pressure to go, as well as from within the Nationals and their Coalition partners, the Liberal Party.

The Nationals - who have until now been able to pride themselves on their stability and aversion to chopping and changing leaders, unlike other major political parties - have been rocked by the scandal around Mr Joyce's personal life.

Related questions about Mr Joyce's use of his travel entitlements, new allegations of harassment by a woman in Western Australia, and the appropriateness of the redeployment of Ms Campion to the offices of senator Matt Canavan and MP Damian Drum, have further damaged the Deputy Prime Minister and contributed to his exit.

The country-based party will begin the process of choosing a replacement for Mr Joyce as leader at a party room meeting in Canberra at 8am on Monday.

Among those being discussed for the post of party leader are MPs Michael McCormack, Darren Chester and David Gillespie.

Addressing a press conference in Armidale, NSW, the member for New England said that "on Monday morning at the party room, I will step down as the leader of the National Party and deputy leader of Australia".

"I have informed the acting Prime Minister, Mathias Cormann, of this. I informed my colleagues of this."

Barnaby Joyce resigns as leader of the Nationals and Deputy Prime Minister at a media conference in Armidale on Friday.Credit: AAP

"I'd like to say that it's absolutely important, it's incredibly important that there be a circuit-breaker, not just for the Parliament, but more importantly, a circuit-breaker for Vikki, for my unborn child, my daughters and for Nat. This has got to stop. It's not fair on them."

Mr Joyce, who was first elected to Senate in 2004, said he would not quit the Parliament but, rather, would head to the backbench and continue work on a book and promised "no, I won't snipe". Considered one of the nation's best "retail politicians", he switched from the Senate to the House of Representatives in 2013, and became leader of the Nationals in 2016, the same year he became Deputy Prime Minister.

Last year he was forced to quit Parliament and contest a byelection after he was found to be a dual New Zealand citizen and therefore constitutionally ineligible for election.

A move to the backbench would mean he would give up the portfolios of Infrastructure and Transport and his salary would drop from $416,000 to about $200,000 a year. The new National Party leader would become deputy prime minister under the Coalition agreement.

The decision to quit comes less than 24 hours after backbench Nationals MP Andrew Broad called on him to quit, and two days after Mr Joyce and Ms Campion granted an exclusive interview to Fairfax Media in which the pair appealed to politicians and members of the public to "move on" from the scandal.

Deputy Prime Minister Barnaby Joyce and Prime Minister Malcolm Turnbull.

That interview had the opposite effect to that intended, stoking anger within the Nationals that the former deputy prime minister - who was supposed to be on a week of personal leave - was instead kicking the story along.

Mr Joyce said he had finally decided to quit following the airing of allegations of sexual harassment in a Sydney tabloid, which he said he had only become aware of "in the last day or so".

"Over the last half a month, there has been a litany, litany of allegations. I don't believe any of them have been sustained," he said.

"The last allegation that was in the paper today, I have asked that that be referred to the police. I've asked for the right of the person who's made the allegation and I've asked for my right of defence that that be referred to the police. But it's quite evident that you can't go to the Despatch Box with issues like that surrounding you."

"I can't enter into any discussions about that. If it is going to be before the courts, it is going to be before the courts."

Soon after the announcement the Prime Minister's office issued a statement thanking Mr Joyce for his service as a "fierce advocate for rural and regional Australia".

"The Coalition between the Liberals and the Nationals is Australia’s most successful political partnership, having endured for more than 95 years," it said.

"This partnership is undiminished and will continue to deliver opportunity and security for all Australians."

Mr Joyce put himself on a collision-course with Mr Turnbull last Friday, when he launched an extraordinary attack on the Prime Minister, calling his comments on the affair "inept", "unnecessary" and "hurtful".