Malcolm Turnbull has said he will quit Australia’s parliament on Friday following his ouster as prime minister by party rivals, local media report.
Mr. Turnbull was replaced by Scott Morrison last week in a bid to end infighting that had crippled the centre-right government.
The ousted leader said Australians would be “appalled” by recent events.
His departure will trigger a by-election and place Mr. Morrison’s parliamentary majority at risk.
In explaining his decision, Mr. Turnbull again took a thinly veiled swipe at his predecessor, Tony Abbott – who had been accused of undermining the government.
“Former prime ministers are best out of parliament not in it, and I think recent events best underline the value of that observation,” Mr. Turnbull told party members on Monday, in a speech reported by multiple outlets.
Without Mr. Turnbull, Mr. Morrison will command 75 of a reduced 149 seats in the House of Representatives.
A by-election for Mr. Turnbull’s seat will most likely take place in October, Australian media reported.
If the government loses the seat, Mr. Morrison will be forced to rely on independents to pass legislation in a 150-member parliament.
The Labour opposition currently has 69 seats.
The seat, Wentworth, has been held by the conservative Liberal Party since World War Two.
However, some say victory for the government is not guaranteed.
In a further twist, Mr. Abbott’s sister, Christine Forster, is reported to be considered running for the seat – but must first be selected by the Liberal Party.
The next general election is due to be held by May, 2019, with opinion polls currently giving Labour the lead.
Germany migrants: Protesters face off in Chemnitz
Rival protests over a murder in the east German city of Chemnitz have ended with several people injured as objects were hurled by both sides, police say.
Far-right activists had gathered in the centre for a second day as a Syrian and an Iraqi remained under arrest on suspicion of Sunday’s deadly stabbing.
Anti-Nazi activists rallied just metres away, accusing the far right of using the death for political ends.
Injuries were caused when protesters on both sides threw objects, police say.
German Chancellor Angela Merkel had warned that “vigilante justice” would not be tolerated.
Police warned masked demonstrators who were picking up stones in the city 190km (118 miles) south of Berlin that their actions were being filmed.
Earlier, the authorities said police were investigating alleged assaults on an Afghan, a Syrian and a Bulgarian during the unrest that broke out on Sunday.
Reports have included mentions of protesters chasing foreigners, though there are few details, and police have appealed for witnesses to the assaults to hand over any video they may have recorded.
It is unclear what triggered a fight which reportedly preceded the stabbing, at about 03:15 (01:15 GMT) on Sunday, on the sidelines of a street festival, which has now been cancelled.
The victim, a carpenter aged 35, was mortally wounded and died in hospital.
Two other German men with him, aged 33 and 38, were seriously hurt, police say.
The Syrian detainee is 23 and the Iraqi 22.
Police have denied rumours on social media that the fight was linked to the sexual harassment of a woman.