Polling booths have opened across Victoria with Treasurer Peter Costello among the first to cast a vote in the federal election.
Victorians, who are among the 13.6 million Australians eligible to vote, started voting at 8am (AEDT), and polling booths will close at 6pm.
Mr Costello, who has been anointed by Liberal leader John Howard to take over as prime minister if the coalition wins today's election, was among the early voters to turn up at the Camberwell Church of Christ Hall, in Melbourne's east.
Mr Costello's next public appearance will be at St Andrew's Uniting Church Hall in suburban Glen Iris tonight when counting gets under way.
Meanwhile, deputy Labor leader Julia Gillard will cast her vote at Seabrook Primary School, in Melbourne's south-west, at 11am (AEDT) today, before flying to Canberra to join experts in the tally room.
Labor must secure an extra 16 seats to win a federal election for the first time since 1993.
It would be only the third time Labor has won from opposition since World War II.