Barnaby Joyce has vowed to fight fresh allegations of sexual harassment against him, saying “if it is going to be before the courts, it is going to be before the courts”.

Amid intense pressure for him to quit, Mr Joyce said on Friday afternoon he would resign as Deputy Prime Minister and Nationals leader, nearly 24 hours after the National Party confirmed he was the subject of a  sexual harassment claim.

“With the last allegation that was in the paper today, I have asked that that be referred to the police,” he told a press conference in Armidale.

“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 while issues like that surrounding you. So, I can’t enter into any discussions about that, as you’ll all understand.

“If it is going to be before the courts, it is going to be before the courts.”

The new allegation against Mr Joyce, which he strongly denies, is said to have been made by a Western Australian woman. The WA Nationals withdrew support for Mr Joyce earlier this week.

Confirming the allegation, the federal National Party said “all complaints are taken seriously” and would be “given due process”.

Over the past two weeks, Mr Joyce has strongly denied various claims of inappropriate behaviour reported in the media, including hinting at possible defamation action.

“Over the last half a month, there has been a litany, litany of allegations,” he said on Friday.

“I don’t believe any of them have been sustained.”

Mr Joyce said he would stay on as the Member for New England, and vowed not to “snipe” from the backbench.

“I have a lot of things I need to do. I’m currently in the process of writing a book about precisely the people I was talking about and I want to make sure I get that concluded,” he said.

“I want to assist my colleagues where I can to keep their seats and also, quite naturally, in April, a baby will be born. I’ll have other things on my mind.”

But he delivered a parting shot to colleagues he believed had leaked against him, saying leaks “destroy not only our government, it will destroy any government”.

Mr Joyce said he was standing down in order to create “clear air” for the National Party to fight for regional people, who he described as those “living in the weatherboard and iron”.

“To give these people in the weatherboard and iron, in those regional and small towns, the best opportunity, then this current cacophony of issues has to be put aside,” he said.

Asked if the media should reveal the affairs of politicians in future, Mr Joyce said the Daily Telegraph had been wrong to print a photo of a pregnant Vikki Campion on its front page.

“And always think of it when you see something like that on paper and you think it’s salacious, think, “What if that was me? My mother, my wife? How would I feel?” 

In a statement, Prime Minister Malcolm Turnbull, who is in Washington D.C., thanked Mr Joyce for his service as “a fierce advocate for rural and regional Australia”.

Relations between the nation’s two most senior government figures hit an all-time low last week when the Prime Minister said Mr Joyce had “appalled all of us”, before the Nationals leader hit back, describing Mr Turnbull’s comments as “inept”.

National Deputy Leader Bridget McKenzie also thanked Mr Joyce for his service on Friday afternoon.

“His decision to stand aside is the right decision for the National Party, the nation and most importantly his family,” she said.