Australian voters will cast ballots Saturday in their most closely contested election in years.

The final polls showed Prime Minister Julia Gillard, the head of the Labor Party, in a virtual tie with the leader of a Liberal Party-led coalition, Tony Abbott.

If she wins, Ms. Gillard will be Australia's first woman to be elected as prime minister. She replaced Kevin Rudd as Labor leader two months ago amid dwindling voter support for the ruling party.

Ms. Gillard has argued that Labor's economic policies brought the country through the global recession better than other developed countries. But Mr. Abbott says the party squandered public money on lavish stimulus programs.

The two candidates also disagree on a proposed mining tax and the composition of a new telecommunications infrastructure.

Ms. Gillard has faced a series of political hurdles, including opposition to the proposed mining profits tax, continued weakness in the economy and animosity from some party members for ousting Mr. Rudd.

During the last day of the campaign Thursday, she praised the government's investment in public services such as health, education and the national broadband network.