"It's in the hands of the people but I'll keep talking to them until six o'clock tonight," he told reporters.
The 68-year-old repeated his message that removing him from office when Australia's economy is booming and unemployment is at a 33-year low was dangerous.
Glimmer of hope
Howard is a close ally of George Bush, the US president and has made a commitment to keep Australian troops in Iraq if re-elected.
He has offered voters $29 billion in tax cuts, but few new policies.
In contrast, the Labor leader Rudd has pledged to withdraw combat troops from Iraq and sign the Kyoto Protocol on global warming.
The 50-year-old former diplomat who speaks Mandarin would also be expected to forge closer ties with China and other Asian nations.
Rudd was due to vote in his home town of Brisbane in Queensland, one of the crucial battlegrounds of the election and has long said that whoever wins will do so narrowly.
Howard was offered a glimmer of hope that he might be able to be returned to power when a new Newspoll showed him halving Rudd's advantage to four per cent.
The poll published Saturday showed Howard's government trailing Labor by 48 percent support to 52 percent, down from an eight point gap just a week ago.
But the results contrasted sharply with a Nielsen survey published on Friday that showed Australia's second-longest serving prime minister heading for a landslide defeat with 43 per cent of support against 57 for Rudd.
Dan Nolan, Al Jazeera's correspondent in Sydney, said that one thing in Howard’s favour is that Australians have never voted out a government when the economy has been going well.
He said that Rudd and his Labor party had run a brilliant campaign and there have been comparisons with Tony Blair’s campaign that ended a long period of conservative rule in the UK in the 1990s.
"If Howard does secure a come-from-behind victory it will not be because of his campaigning skills but because Australians do not want to change the government when the economy is going so well," he said.
|Howard has made a commitment to keep|
Australian troops in Iraq if re-elected
Labor needs to win an extra 16 seats to take office and both Howard and Rudd say the election will be very close, possibly decided in a handful of marginal seats.
Howard once described himself as "Lazarus with a triple bypass" for his ability to be resurrected from political defeat.
But he could also face the humiliation of losing his parliamentary seat of 33-years after new constituency boundaries turned his Sydney stronghold into a marginal seat.
Rudd, 50, is offering voters a generational change, saying Howard is too old and tired to lead Australia.
"I offer Australia new leadership for the future, a positive plan for the future because Mr Howard's government's best days now lay behind it," Rudd said on Friday.
"Mr Howard has gone stale in his government's approach to the future."
13.5 million people are eligible to vote from Australia's remote outback to the Antarctic.