Australia’s scandal-hit deputy leader Barnaby Joyce announced on Friday he was quitting and moving to the backbench amid claims of sexual harassment and controversy over an affair with a now-pregnant former aide. Joyce, whose National Party rules alongside Prime Minister Malcolm Turnbull’s Liberals, has been front-page news in Australia for two weeks since it emerged he had left his wife of 24 years for his younger former media adviser, who is now expecting their baby boy. The 50-year-old had insisted he would ride out the storm but his position became untenable on Friday when a sexual harassment complaint against him, which he denies, was lodged with the party. “I will say on Monday morning at the party room [meeting], I will step down as the leader of the National Party and deputy leader of Australia,” Joyce said at a press conference in Armidale, his country New South Wales electorate. This has got to stop. It’s not fair on them. It’s just completely and utterly unwarranted Barnaby Joyce “It’s incredibly important that there be a circuit-breaker, not just for the parliament, but more importantly, a circuit-breaker for Vikki (his lover), for my unborn child, my daughters and for Nat (his wife). This has got to stop. It’s not fair on them. It’s just completely and utterly unwarranted, the sort of observation that’s happened.” Joyce, who has also been criticised for living in an apartment rent-free with now partner Vikki Campion after splitting with his wife, was due to be the acting prime minister this week with Turnbull in Washington meeting US President Donald Trump. But he opted to take leave. With Foreign Minister Julie Bishop also out of the country, the role has been assumed by Senate leader Mathias Cormann, who said ahead of Joyce’s decision that any harassment claim must be taken seriously. “Any allegation of sexual harassment is a very serious allegation,” he told reporters. “I understand that a formal complaint has been made, and that that complaint is being investigated. I mean, at this point, that is really all that I have to say about it.” Joyce called the allegation “spurious and defamatory” and he wanted it investigated by the authorities. “I have asked that that be referred to the police,” he said, while admitting it had been “the straw that broke the camel’s back”. “It’s quite evident that you can’t go to the despatch box with issues like that surrounding you,” he said. His decision to quit came with colleagues reportedly growing increasingly frustrated with his handling of the love-child scandal. In a statement from Washington, Turnbull thanked Joyce for being “a fierce advocate for rural and regional Australia”, while insisting the Nationals-Liberal coalition was “undiminished” by the scandal. Australia bans sex between government ministers and staff as scandal with deputy PM Barnaby Joyce and pregnant ex-aide deepens But Labor opposition leader Bill Shorten called it “fundamentally damaged” and accused Turnbull of “an atrocious lack of judgement”. “The fact that this scandal has dragged on for 16 days has been damaging to the government, but more importantly, the country,” he said. Junior Nationals minister David Gillespie has indicated he would be a candidate for the vacancy, while reports said Veterans Affairs Minister Michael McCormack had significant backing. The new Nationals leader will automatically become deputy prime minister, under a coalition agreement between the two major parties of the centre-right.