Scott Morrison and Bill Shorten will duke it out in a prime-time debate expected to garner the most eyeballs of the election's three verbal stoushes.
After close contests in two debates last week, the prime minister and Labor leader will have their final televised showdown at the National Press Club in Canberra on Wednesday night.
Press Club president and ABC journalist Sabra Lane will be the sole moderator of the one-hour debate, which will focus on domestic and international policies of both major parties.
Undecided voters gave the first two debates, which were in Perth and Brisbane, to Mr Shorten - the first by a 2-to-1 margin and the second narrowly.
Mr Morrison is expected to continue needling Labor's reforms to the tax system and talk up the coalition's perceived strength in economic management.
Mr Shorten's campaign has focused on health and education spending promises, along with driving up wages through industrial relations law changes.
Both men say this election is all about choice.
The moderator will determine the debate topics which are expected to include leadership, the economy, employment, energy and climate change, immigration, indigenous affairs and foreign affairs.
The leaders, who will stand behind lecterns, also get to ask two questions of each other during the debate.
Prime Minister Scott Morrison and Opposition Leader Bill Shorten went head-to-head for the first time during the campaign in Perth. Source: AAP
Answers to questions will be a maximum of two minutes each with a further one minute rebuttal.
More than one million people are expected to have voted by the time the debate kicks off at 7.30pm AEST.
Earlier in the day, the leaders are likely to be campaigning in regional NSW.
Mr Shorten is announcing Labor would tip $250 million into a "better care fund" pay incentives to hospitals, specialists and primary healthcare providers giving better, faster care.
