Malcolm Turnbull will remain Australia's Prime Minister after defeating a leadership challenge from hard-line Immigration Minister Peter Dutton, 48 to 35.
12.10pm: It is understood at least four other ministers could join Peter Dutton on the backbench, having supported him in the ballot against Malcolm Turnbull. It means a Cabinet reshuffle is now an almost certainty. Mr Turnbull and Mr Dutton are both declining to speak at this time. For now, that concludes our live coverage of this story. Thanks for tuning in.
11.50am: Peter Dutton has resigned as Home Affairs and Immigration Minister after his failed leadership bid. He will leave the government's frontbench.
11.40am: The prime minister declared the leadership vacant after entering the party room with his deputy Julie Bishop shortly after 9am (AET) on Tuesday morning.
Party whip Nola Marino confirmed Mr Turnbull won 48 votes to 35 for Mr Dutton.
"He thanked his colleagues for their support," Ms Marino said.
Julie Bishop retained the deputy leadership.
11.35am: The vote was held in secret just after 11am (NZT).
The challenge came after Mr Turnbull called a spill, with Mr Dutton putting his hand up to challenge.
Turnbull's leadership under threat
11.20am: Despite Mr Turnbull's capitulation to energy policy rebels in his ranks, the expectation his leadership is under threat has grown.
Cabinet minister Christopher Pyne said earlier Mr Dutton had told him the prime minister has his absolute support.
"I'm certain he is telling the truth," he told the Nine Network.
Mr Pyne described his Liberal colleagues stoking leadership tensions as "cowards".
"I think the public would react very negatively to another change of leadership without them having a vote."
A report in The Australian suggests Mr Turnbull had lost confidence of nine Liberal cabinet ministers - half of the Liberal contingent.
Mr Dutton's camp believed it could get to the 43 votes needed to oust Mr Turnbull, but the prime minister's backers said he still had majority partyroom support. Ultimately, they were correct.