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CANBERRA, Australia (AP) — Julia Gillard became Australia's first female prime minister by overthrowing her former boss less than two months ago and called elections just weeks later — a strategy meant to save the left-leaning government from rising voter grumbling by installing a fresh, straight-talking leader. It hasn't quite worked out that way.

Instead, conservative opposition leader Tony Abbott — once considered too much of a loose cannon to lead, even by his own colleagues — has made the contest to be decided Saturday one of the closest in decades with a campaign that offers Australians a stark choice in leaders.

Gillard faces a backlash at the ballot box over a range of voter gripes including lingering anger over her unprecedented coup and her policy direction on climate change.

But most analysts expect her center-left Labor Party will hang on to power for a second three-year term with a slim majority.

Gillard stunned Australians — including many within her government — when she launched a sudden challenge to Prime Minister Kevin Rudd's leadership on June 24. She had been his deputy.

He surrendered without a fight on realizing that his support among government colleagues had collapsed along with the party's popularity in opinion polls.

Gillard soon called an election with a campaign slogan "moving forward," explaining that she wanted the voters' mandate for her leadership.

But moving forward from the leadership mutiny has proved problematic for her party. Gillard's five-week campaign has been repeatedly distracted by damaging media leaks, apparently from well-placed anonymous government sources, which have been blamed on Rudd or Rudd loyalists.

Rudd has denied any part in the treachery, which has been cited by Abbott as evidence of a bitterly divided and dysfunctional government.

Rudd's political ghost continued to cast a shadow over Gillard's campaign this week when his 26-year-old daughter Jessica Rudd launched her debut novel about a fictional Australian prime minister who is overthrown by his female deputy. The author explains that she finished the book in December last year and its similarity to reality was purely coincidental.

Nick Economou, a Monash University political scientist, said continuing media attention on Rudd's demise reminds voters of their anger that the leader they had chosen had been taken from them.

"The big strategic weakness in the Labor campaign has been the failure to satisfactorily explain the change of leader and I think that's certainly going to hurt Labor and Gillard in Queensland," Rudd's home state, Australian National University political scientist Norman Abjorensen said.

Pollster Martin O'Shannessy, chief executive of the respected market researcher Newspoll, predicted Labor would scrape through the election with a four or five seat majority in the 150-seat House of Representatives. Labor cruised to power in 2007 with 83 seats after 11 years in opposition.

O'Shannessy said Rudd's popularity plummeted in Newspoll surveys since May after he shelved plans to make big polluters pay for the carbon gas they emit. The poor polling created Gillard's chance to strike.

But Labor's rebound in the polls under Gillard proved short-lived after she announced in the first week of the election campaign that greenhouse gas polluters will not be charged during Labor's second term.

Reneging on the key promise of Labor's 2007 election campaign to make polluters pay had created "a leadership crisis," O'Shannessy said.

"People are saying this leadership isn't what we signed up for," O'Shannessy said.

Undeterred, Abbott is telling voters that Labor would introduce a carbon tax that will lead to higher power bills for everyone.

Abbott, who doubts the science behind climate change, is a stark contrast to Gillard. While he was long considered too far right to appeal to the Australian political middle ground, Gillard has wrestled her reputation for being too far to the left.

Abbott is his Liberal Party's third leader since it lost power and the first to threaten the government in opinion polls.

The athletic 52-year-old is often pictured cycling in Lycra or swimming off Sydney beaches and is widely regarded as a man's man who struggles to attract female voters.

He once studied to become a Roman Catholic priest but is now married with three daughters. A social conservative, he regrets that divorce has become easily available under Australian law.

Gillard, 48, is a Welsh-born former Baptist turned atheist and became the first prime minister in the 109-year history of the Australian parliament to take an affirmation of office instead of swearing on a Bible.

She will become the first prime minister to move into the official residence in the national capital with a common law spouse if she wins elections.

She has repeatedly denied suspicions that she was a communist in her 20s and has refused to answer media questions about whether a former sexual relationship she had with a Labor colleague Craig Emerson, now a minister in her cabinet, began before or after he had separated from his wife and children. Emerson refuses to discuss with the media his two-year sexual relationship with Gillard.

She was widely acknowledged at the government's best communicator and Rudd's natural successor.

To an extent, history favor's Gillard since no first-term Australian government has been voted out since 1931 when a Labor administration paid the price for the Great Depression.

But while Australians traditionally give their governments a second chance, no Labor government has ever before turned on a first-term prime minister.