Prime Minister John Howard and opposition Labor leader Kevin Rudd are entering the final days of their general election campaigns. What issues are likely to prove decisive for Australian voters?
The strength of the economy has been something of a trump card for Mr Howard, and has been central to his campaign.
On announcing the election, he said Australia was, by common agreement, "enjoying a remarkable level of national prosperity".
More than 13.5m of Australia's roughly 21m people are registered to vote
Electors will choose candidates for all 150 seats in the lower House of Representatives and 40 of the 76 seats in the upper house, the Senate
PM John Howard has led the conservative Liberal-National party coalition to four election wins since 1996 and is seeking a final term
Kevin Rudd is taking the centre-left Labor Party to the polls for the first time as leader
With stock markets riding high and unemployment at a 33 year low, he certainly had a strong case.
But an interest rate rise - taking it to an 11-year high - has hampered Mr Howard, who has promised that rates would always be lower under a Liberal government.
Mr Rudd, who says he is an "economic conservative", has argued that the government is "failing to fight effectively against the inflation threat to the economy".
He says "working families on home mortgages" are paying the price.
Both candidates have pledged tax cuts and promised to help working families with tax relief.
Mr Howard was first with his announcement of a five-year plan for cuts worth A$34bn (£15bn), part of his "go-for-growth" strategy.
Labor reacted with a promise of A$31bn, only to be accused by Mr Howard of copying his policies.
Australian voters will have to decide between Mr Howard's claim that he has the experience to manage the economy, and Mr Rudd's brand of economic conservatism.
Australia has a large and vocal environmental lobby
Australians are the world's worst polluters per head, according to data from US think tank Center for Global Development.
Some parts of the country are already experiencing record drought conditions, with some groups blaming climate change.
The drought has created financial hardship for farmers and forced some people to move away from affected regions.
This, combined with rising global concern over climate change, is making environmental issues more important than ever in this election campaign.
The environment has been a particularly challenging election issue for Mr Howard, and is seen as a vote-loser for him.
His refusal to sign the Kyoto agreement has been widely criticised, but he insists that Australia must balance climate obligations with economic interests.
He believes any agreement which does not include China and India is worthless.
Mr Howard has also proposed a shift towards nuclear power, arguing that Australia, which sits on the world's largest known uranium reserves, would be "crazy in the extreme" if it ruled out development of nuclear generators.
Mr Rudd has pledged to protect the Barrier Reef if elected
Mr Rudd was initially all-but guaranteed the green vote by opposing nuclear power and insisting he would immediately ratify Kyoto if elected.
He has insisted that Labor is "committed to coal" and will invest in new clean coal technologies.
He also boosted his popularity with the green vote by pledging to spend A$200m (£90m, US$185.5m) on a rescue and protection plan for the Great Barrier Reef.
But he was put in an embarrassing situation when his environment spokesman, Peter Garret, said Labor would sign any future agreement on carbon emissions, whether or not it included India and China.
Mr Rudd was forced to deny this, citing exactly the same concerns as Mr Howard, who described the move as "unbelievable capitulation".
In 2003, Mr Howard's decision to send Australian troops to join the US-led invasion of Iraq provoked widespread public opposition.
He claimed the war would make Australia less likely to suffer a terrorist attack - his opponents believed it would make the country a target.
Mr Howard has been unflinching in his support for the war - about 1,600 military personnel in and around Iraq.
Two soldiers have died in accidents since the Iraq war began
Opinion polls over the past four years have fluctuated - with Mr Howard's stance often the more popular.
But his case was not helped earlier this year when a senior cabinet member said oil was a major reason for Australia's involvement - something the US has gone to great lengths to deny.
Most of the criticism of his foreign policy has focused on what critics have portrayed as his slavish devotion to the US.
Labor argue that there was never a strong enough case for going to war in Iraq.
Mr Rudd has described the decision as the "single greatest error of Australian national security and foreign policy decision-making since Vietnam".
He has promised to initiate a phased withdrawal of troops from Iraq, and claims the Howard government is "making it up as it goes along".
However, Iraq is unlikely to be the main focus of voters' concerns - perhaps because no Australian soldier has been killed as a result of enemy action.
Immigration has been a hot issue in Australia for many years, with ongoing debates over how many people should be allowed into the country, and on what grounds they should be accepted.
John Howard has generally taken a tough stance on the issue - introducing citizenship tests and controversial off-shore processing for refugees and asylum seekers.
Australia announced a freeze on the settlement of immigrants from Africa this year, on the grounds they had trouble integrating, and that trouble spots closer to home should be a priority.
Mr Howard also proposed a ban on HIV-positive migrants from entering the country, a suggestion which prompted angry reactions from Aids charities.
His policies have been variously applauded and criticised by the public.
Labor says the government fails to properly help immigrants to settle in the country.
The party has pledged almost $50m to reforming the system of teaching English to new arrivals and helping them to find jobs.
Australia is a predominantly Christian country, with more than five million people identifying themselves as Catholic and four million as Anglican. Both Mr Howard and Mr Rudd are practising Christians.
The Christian vote is influential, but Australia does not have the sort of hugely influential Christian lobby that has had such an impact on American politics.
In an indication of the importance of the Christian vote, John Howard and Kevin Rudd took part in a live debate in August which was broadcast in 800 churches and seen by about 100,000 people.
Mr Rudd and Mr Howard both say they oppose same-sex marriage, garnering praise from conservative Christian groups.
"Love me or loathe me, the Australian people know where I stand on all the important issues of their future," Mr Howard told a press conference after announcing the election.
Whether or not that is the case, there is a clear mood for change among some areas of the population and Mr Rudd has consistently had the lead in opinion polls.
Mr Howard, at 68, has been in office since 1996 and has himself said he would retire during his next term in office.
But, Australia is not a country that deposes its leaders lightly.
In the past 24 years, there has been only one change of governing party, and the incumbent government has lost in only four of the 23 elections since 1949.
The BBC's Nick Bryant, in Sydney, says Mr Howard is known for his political resilience.
Mr Rudd has made change a centrepoint of his campaign, saying the country needs "fresh ideas to deal with Australia's future challenges".
Even in Mr Howard's Bennelong constituency, which has elected him in 13 consecutive elections, some voters have said that Howard has "done his dash" and they are due for a change in leadership.
But, he said, the country's best years could be ahead.
To secure that, he added, Australia did not need new leadership or old leadership, but "the right leadership".