Australia's Tony Abbott ousted from office in internal party challenge

The change at the helm will also likely lead to a major cabinet reshuffle, with Treasurer Joe Hockey, Finance Minister Mathias Cormann, Defense Minister Kevin Andrews and Employment Minister Eric Abetz among ministers who publicly supported Abbott against the Turnbull challenge.

Abbott's former Liberal Party deputy, Foreign Minister Julie Bishop, who supported Turnbull's bid, was re-elected party deputy. She defeated Andrews 70 votes to 30.

The Liberals were elected in 2013 as a stable alternative to the then-Labor government. Labor came to power under Kevin Rudd after elections in 2007, only to dump him for his deputy Julia Gillard in 2010 months ahead of elections. The bitterly divided and chaotic government then dumped Gillard for Rudd just months before the 2013 election.

Before Rudd was elected in 2007, John Howard was in power for almost 12 years.

Monday night's contest pitted a man who has been described as the most socially conservative Australian prime minister in decades against a challenger some think is not conservative enough.

Unlike Abbott, Turnbull supports gay marriage, wants Australia to replace the British monarch with an Australian president as head of state and backs a policy of making polluters pay for their carbon gas emissions.

“This country needs strong and stable government and that means avoiding at all costs Labor's revolving-door prime ministership,” Abbott told reporters before the ballot, referring to the opposition Labor Party that changed its prime minister twice in three years.

“The prime ministership of this country is not a prize or a plaything to be demanded. It should be something which is earned by a vote of the Australian people,” he added.

Turnbull earlier said the government was doomed to defeat with Abbott as leader.

“Ultimately, the prime minister has not been capable of providing the economic leadership our nation needs,” Turnbull told reporters. “He has not been capable of providing the economic confidence that business needs.”

The government has trailed the opposition in a range of opinion polls since April last year. Abbott survived a leadership challenge from within his party in February that was prompted by those polls and what some say were questionable judgments he made. At the time, Abbott asked his colleagues to give him six months to improve his government's popularity.

That deadline passed without a change in polling. General elections are due around September next year.

Turnbull, a 60-year-old former lawyer and merchant banker known for his moderate views, has long been considered Abbott's chief rival. Turnbull was opposition leader for two years before he lost a party-room ballot by a single vote to Abbott in 2009. His downfall was his belief that Australia should make polluters pay for their greenhouse gas emissions, a position that split the coalition.

Opinion polls show that Turnbull is more popular than Abbott, but many of those who prefer him vote for the center-left Labor Party.

Abbott and Turnbull are both Rhodes scholars. Abbott, a 57-year-old former Roman Catholic seminarian, has long suffered an image problem, particularly among women. He is regarded as gaffe-prone and old-fashioned in his views on women's place in society.

Turnbull is a self-made multimillionaire regarded by some as arrogant and has been nicknamed “The Silvertail,” an Australian term for wealth and privilege.

The Associated Press