Up to 80,000 uncounted votes in four doubtful seats will determine which of the two major parties forms a minority government in Australia's first hung parliament in 60 years.
If the numbers fall Labor's way, Prime Minister Julia Gillard will be in a position to form a government with the support of an Australian Greens MP and one of possibly four independents.
There also is a possibility Opposition Leader Tony Abbott could form a minority coalition government with the support of at least three independents.
When the counting of votes ceased at 2.00am (AEST) on Sunday the coalition had 71 of the 150 seats in the lower house, Labor had 70, there were likely four independents and a Green.
There are four seats, all held by the government, that are too close to call.
Labor is leading in two of the seats - Lindsay (NSW) and Corangamite (Vic) - while the Liberal Party leads in Brisbane (Qld) and Hasluck (WA).
Neither Ms Gillard or Mr Abbott was able to claim victory on Saturday night.
A record number of pre-poll and thousands of postal votes have yet to be counted, meaning a final result may not be known until the end of next week.
The prospect of a hung parliament has been welcomed by Independent MP Rob Oakeshott.
"It's a very exciting and enlightening moment," he told Sky News on Sunday.
The NSW MP intends travelling to Canberra later on Sunday for talks with two other independents Tony Windsor (NSW) and Bob Katter (Qld).
Mr Windsor said he had received a phone call from Ms Gillard and Liberal frontbencher Joe Hockey, both congratulating him on his win in New England.
Labor lost its hold on government on the back of a national 2.01 per cent to the coalition, less than the 2.3 per cent the opposition needed to win power in its own right.
Big swings against Labor in NSW (4.0pc), Queensland (5.0pc) and the Northern Territory (4.8pc) cost the government dearly.
A smaller-than-expected swing in Western Australia (1.7pc) limited Labor losses to one or two seats.
But the losses were offset by swings to the government in Victoria where Labor has won two seats from the coalition (0.88pc), Tasmania (4.81pc) and South Australia (1.15pc).
The coalition outpolled Labor on the primary vote by about 400,000 votes but fell behind the government 49.3 to 50.69 per cent after the distribution of preferences.
Opposition frontbencher Scott Morrison told Network Ten majority coalition government would be "a stretch" for the coalition but forming a minority government was a possibility.