Australia’s “unelectable” and gaffe-prone political leader, Tony Abbott, confounded critics on Saturday by becoming the country’s latest Prime Minister, leading the opposition to a sweeping election victory and ending six years of Labour Party rule.

Mr. Abbott, the leader of the conservative Liberal Party-led coalition, rode a wave of public bitterness over a hated carbon emissions tax, worries about a flagging economy and frustration over government infighting to win the election.

The result was a stunning turnaround for Mr. Abbott, a 55-year-old former Roman Catholic seminarian and Rhodes scholar who has never been particularly popular and was once dubbed unelectable by opponents and some of his own supporters.

“I now look forward to forming a government that is competent, that is trustworthy and which purposefully and steadfastly and methodically sets about delivering on our commitments to you the Australian people,” Mr. Abbott told supporters in his victory speech on Saturday night.

With more than 90 per cent of votes counted, official figures from the Australian Electoral Commission showed the Liberals ahead 53 per cent to Labour’s 47 per cent. The coalition was on track to win 91 seats in the 150-seat House of Representatives, and Labour 54.

For a range of reasons, Mr. Abbott has been dismissed by many critics as not being Prime Minister material. A supremely fit volunteer lifeguard, he is often parodied in the media for wearing the red-and-yellow cap and brief swimwear worn by Australian lifeguards.

Mr. Abbott’s approval ratings recently improved in polls, but he remains relatively unpopular, particularly among women voters.

“All those ridiculous people who said he was unelectable should understand how foolish they were to underestimate him,” former conservative Prime Minister John Howard, who promoted Mr. Abbott to his Cabinet during an 11-year reign, told Seven Network television on Saturday.

Mr. Abbott was regarded as a competent Minister. But his aggressive politics, social conservatism and knack for igniting controversy raised questions about his suitability as a potential national leader. He was elected party leader by his Liberal Party colleagues in late 2009 by a single vote majority.

In the latest campaign, he was criticised for listing a female candidate’s “sex appeal” as a political asset, then defending himself by calling it a “charming compliment.” In another incident, he accidentally drew laughter during a speech by saying that no one is the “suppository” of all wisdom, when he apparently meant to say “repository.”

But the drama between Mr. Rudd and Ms. Gillard, combined with Labour reneging on an election promise by imposing a deeply unpopular tax on the nation’s biggest carbon polluters, proved deadly for Labour’s re-election chances.

Mr. Abbott, who becomes Australia’s third Prime Minister in three months, will likely end a period of extraordinary political instability and apparent chaos in Australia.

The voter swing away from Labour was a resounding rejection of Australia’s first minority government since World War II. Voters disliked the deals and compromises struck between Labour, the minor Greens party and independent legislators to keep their fragile, disparate and sometime chaotic coalition together for the past three years, including the carbon tax.

Mr. Abbott has vowed to scrap the carbon tax from July 2014 two years after it was implemented and instead introduce taxpayer-funded incentives for polluters to operate cleaner.

It is unclear whether Mr. Abbott will be able to pass the necessary law changes through Parliament, but he has threatened to call early elections if the Senate thwarts him.

Australia’s new leader inherits a slowing economy, hurt by the cooling of a mining boom that kept the resource-rich nation out of recession during the global financial crisis.

Mr. Abbott has promised to slash foreign aid spending as he concentrates on returning the budget to surplus. Labour spent billions of dollars on economic stimulus projects to avoid recession. But declining corporate tax revenues from a slowdown in mining forced Labour to break a promise to return the budget to surplus in the last fiscal year.

Mr. Abbott has also promised to repeal a tax on coal and iron ore mining companies, which he blames in part for the downturn in the mining boom. The 30 per cent tax on the profits of iron ore and coal miners was designed to cash in on burgeoning profits from a mineral boom fueled by Chinese industrial demand. But the boom was easing before the tax took effect. The tax was initially forecast to earn the government AU$3 billion Australian ($2.7 billion) in its first year, but brought in only AU$126 million after six months.

Saturday’s election likely brought Australia’s first Aboriginal woman to Parliament. Former Olympian Nova Peris is almost certain to win a Senate seat for Labour in the Northern Territory, but the final results will not be known for days. Less likely is WikiLeaks founder Julian Assange’s bid for a Senate seat in Victoria State.

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