Barnaby Joyce steps down as Australia's deputy PM and leader of the National Party.

Barnaby Joyce has bowed to the inevitable and finally resigned, quitting the Deputy Prime Ministership and Australian Prime Minister 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 Joyce's personal life.

MICHAEL MASTERS/GETTY IMAGES Barnaby Joyce is even facing revolt from inside his own party.

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

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The country-based party are now expected to choose a replacement for Joyce as leader at a party room meeting in Canberra on Monday, with NSW Michael McCormack, Victorian MP Darren Chester and NSW MP David Gillespie among those being discussed for the post of party leader.

SUPPLIED Joyce has faced no end of bad press since the scandal broke.

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."

Joyce said he hoped the resignation would serve as a circuit breaker for Campion,his wife Natalie Joyce, his four daughters and his unborn son.

SUPPLIED Barnaby Joyce has faced criticism from all directions for his relationship with a former staff member.

The decision to quit comes less than 24 hours after backbench Nationals MP Andrew Broad called on him to quit, and two days after Joyce and Campion appealed to politicians and members of the public to "move on" from the scandal.

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.