Counting of votes began for Australia's federal election on Saturday, which was the tightest federal elections in Australian political history.

Votes from southeastern states will be the first to be counted after the close of polls at 6:00 p.m. local time (0700 GMT), with the other states and territories in different time zones set to follow.

The results in marginal seats in both states are expected to determine the make-up of the new House of Representatives.

Prime Minister Julia Gillard and his opponent, Australian Coalition Leader Tony Abbott cast their votes in Melbourne and Sydney respectively, with both predicting a "very close" result.

A Sky News exit poll, conducted by Auspoll in 30 marginal seats, showed Labor led Coalition by 51 percent to 49 percent on a two party preferred basis. The primary votes showed the coalition with 45 percent, Labor with 42 percent, and the Greens with 9 percent.

"This batch of seats is a bit tougher for the Labor party, a bit better for the Liberal Party. So it would be more like 52-48 nation wide (to Labor)," Auspoll analyst John Armitage told Sky News on Saturday.

Meanwhile, Nine Network's exit poll revealed that Labor Party led the Coalition by 52 percent to 48 percent on a two party preferred basis.

Accoding to ABC Network, uniform swing of 2.5 percent against Labor Party nationally would be enough to deliver a hung parliament, with the balance of power likely to rest in the hands of three independents and possibly a Greens Member of Parliament.

A total of 14,030,528 voters have chose from 1,198 candidates for all the 150 seats in the House of Representatives and 40 of the 76-member Senate.

The electoral commission Friday night said a record number of Australians have already voted. About 2 million of the 14 million who are enrolled have cast their ballot in a pre-poll vote process. In close seats between the two parties, it could mean the result may not be known on Saturday's night.