SYDNEY – Australia awoke to the prospect of its first hung parliament in 70 years on Sunday after a voter backlash against Prime Minister Julia Gillard, who ousted an elected leader just eight weeks ago.

Gillard, who became the country's first woman prime minister in a party coup, was lagging behind her conservative rival in national polls by 70 seats to 72, according to public broadcaster ABC.

The Labor leader, 48, conceded her center-left party would not gain the 76 seats needed for an outright majority and would have to rely on the support of parliament's projected four independent lawmakers.

"The people have spoken, but it's going to take a little while to determine exactly what they have said," Gillard told supporters in Melbourne.

"What we know from tonight's result is there will be a number of independents in the house of representatives playing a role as the next government of Australia is formed."

Analysts said Australia could be in limbo for up to two weeks as parties horse-trade for leadership of the 150-seat lower house, after Gillard's Labor became the first single-term government since 1932.

"What is clear tonight is that the Labor Party has definitely lost its majority," opposition leader Tony Abbott, of the Liberal/National coalition, told cheering supporters in what smacked of a victory speech.

The events represent a stunning reverse for Labor, which swept to power in 2007 under Kevin Rudd but then enraged voters by dumping the then-prime minister in June, after his approval ratings slumped.

Gillard quickly called elections, hoping for a honeymoon with voters, but her campaign failed to capitalise on Labor's big achievement -- helping Australia avoid a recession during the financial crisis.

The electoral upset that robbed Labor of its majority was "a referendum on the political execution of a prime minister" by Labor's factional leaders, Abbott told his supporters, while urging them not to be triumphalist.

Voters were also incensed by Labor's decision to shelve an emissions trading scheme, the centrepiece of its drive against climate change, after failing to push it through parliament.

Around 14 million electors took part in a mandatory vote for the lower house and half of the 76-seat Senate.

Results showed voters turning on Labor in the battleground states of Queensland and New South Wales, but stronger support for the Greens, which favors the ruling party under Australia's complex preference voting system.

The Greens took more than 11% of the vote -- a record for them -- and Adam Bandt, who won the inner city seat of Melbourne for the party, said their success was a "resounding verdict" on the climate change policies of the major parties.

Gillard, a former lawyer and "Ten Pound Pom" who was born in Wales, had pledged better education and healthcare and played up Labor's handling of the economy during the global financial crisis.

Abbott, a 52-year-old religious conservative who has doubts about mankind's role in climate change, targeted fears over illegal immigration and questioned Labor's spending record, as well as Gillard's knifing of Rudd.

The coalition needed a uniform swing of 2.3% to return to power less than three years after Rudd's decisive election win against the Liberals' John Howard, who was prime minister for 11-and-a-half years.

Three independent MPs were confirmed to have won their seats by the Electoral Commission, as was one Green MP. A fourth independent was projected to win by ABC.

Experts said Australia was set for a period of instability with the first hung parliament since World War II, the result which had been most dreaded by the financial markets.