Australian Prime Minister Malcolm Turnbull has warned of the risk of an unexpected result while Labor leader Bill Shorten has had to defend his leadership ahead of tomorrow's election.

Turnbull told the National Press Club in Canberra yesterday that Australians risk ending up with a result they didn't see coming if they vote for minor parties.

Shorten, meanwhile, has been is fending off talk that his days as Labor leader are numbered, even before a vote is counted.

Under Labor rules agreed in 2013, Shorten will be forced to spill the leadership if he loses the election. News Corp newspapers yesterday reported Anthony Albanese could mount a leadership challenge if Shorten did not at least achieve a hung parliament. He said Labor was "unarguably the most united we've been in probably two decades". But despite national polls remaining neck-and-neck in the final week of the campaign, the serious money is behind the Turnbull Government maintaining its majority, with Labor's odds of winning at $8, according to one betting agency, and the Liberal-National Coalition at $1.08. To become government, Labor needs to pick up a net 21 seats from the Coalition.


Turnbull echoed sentiments in the wake of the British referendum to leave the European Union, as he told the National Press Club that the election was a critical choice for the nation.

People should carefully consider the impact of their vote on practical policy outcomes and the workability of the Parliament.

"Australians won't want to end up next week with a result they didn't see coming," he said.

Voting for minor parties would be a roll of the dice that could result in Shorten as prime minister, with unions, Greens and independents pulling the strings, he said. "This threat is real."

Turnbull said it was worth remembering that Australia had not had a strong majority government returned to office at an election going back to 2007.

He pleaded with the public not to vote for candidates they didn't know.

"Leave it to independents and preferences to decide, and Australians will find themselves this time next week with no clarity about their future," he said.

Shorten, meanwhile, received a boost of sorts from an unlikely source, with conservative radio host Alan Jones congratulating him for running an "energetic" campaign and motivating the party.

Jones also told Shorten that he agreed with some of the Opposition leader's points - about a costly plebiscite on gay marriage and revenue needed to pay for company tax cuts.

"This, I think, is a very valid point that Mr Shorten has not received appropriate credit for," Jones said on the latter issue.

The Labor Party opposes the conservative Government's plan to hold a plebiscite this year to allow the public a direct say on whether Australia should give legal recognition to same-sex marriage.

Labor's position now is that Parliament should make the decision.

On Wednesday Shorten said: "I think the people of Australia, the majority of them, have clearly moved - even in the last two or three years - to supporting marriage equality and all popular opinion polls would seem to indicate the truth of what I'm saying."

Some Australians will be forgiven for heaving a sigh of relief after casting their vote.

Turnbull kicked off the election campaign on May 8, making it the second-longest in Australian history. Only Bob Menzies in 1954 forced the country to endure a longer match - an epic 94 days.

This year's race has been a contest of four novices - Turnbull, Shorten, National's Barnaby Joyce and the Greens' Richard Di Natale - none of whom has previously led their parties into an election.

It was also the third consecutive election called by a prime minister who took office mid-term after cutting down their predecessor.

And it is only the seventh double-dissolution election in Australian history and the first since 1987.

Malcolm Turnbull waves after his speech during his Liberal Party election campaign launch in Sydney. Photo / AP
Malcolm Turnbull waves after his speech during his Liberal Party election campaign launch in Sydney. Photo / AP

Turnbull and Shorten two peas in a pod ... to a point

Malcolm Turnbull and Bill Shorten have quite a bit in common.

They're both from broken homes, though each had one loving and supportive parent. Both went to top schools and universities.

And both were already prominent figures when first elected to Parliament - Turnbull through the Spycatcher trial, the republican movement and various financial power plays, and Shorten through the Beaconsfield mine collapse.

In this they are unusual. Of all Australia's prime ministers, at least of the past 60 or so years, only Bob Hawke would have had a higher profile pre- Parliament.

Some of the most important - Malcolm Fraser, Paul Keating, John Howard - were, comparatively, callow youths unknown beyond their immediate family and political circles when their parliamentary careers started.

Fraser and Keating, both 25 when first elected, had little experience beyond politics.

Turnbull is particularly unusual in that he was 49, with several distinct and successful careers behind him, when he entered Parliament.

Shorten, after the common Labor career path through the union movement, was 40.

Turnbull's been very good at making money, a skill less obvious in Liberal politicians than may be expected. They are, or so Labor would have us believe, the party of the big end of town.

Generally, the Liberals have preferred political skills.

But political skills aren't always inherited.

The political gene ran deep in Kim Beazley, Alexander Downer and Simon Crean. But none of them, though becoming party leader, quite made it to the top job.

Turnbull is untroubled by such genes and Shorten has them only lightly.

All this so far suggests that prime ministerial contenders are divided more by rhetoric than substance.

But there seems to be one big difference.

Labor challengers win when they can excite and enthuse.

Whitlam's powerful presence - quite apart from the "it's time" factor - overpowered Billy McMahon. Hawke, the confident larrikin, ran rings around the dour Fraser. Kevin Rudd, whatever you think of his Government, looked young and fresh and full of beans against a Howard who'd got into the ring once too often.

Liberal challengers, on the other hand, do best promising to fix up Labor's mess. Fraser was the beneficiary of Whitlam's excesses and Tony Abbott destroyed what was left of the Rudd-Gillard-Rudd Government.

Howard was a little different against Keating in 1996. But by promising to make people relaxed and comfortable, he was rejecting the politics of charisma.

Perhaps this means voters are fickle - they want to be excited by the prospect of Labor in office but once they experience it they want to retreat to the comfortable Liberal embrace.

Which would be good news for Turnbull, because Shorten hasn't exactly set the crowds alight.

The PM, meanwhile, has suppressed the passion he once let loose and carried on interminably about jobs and growth.

History's lesson: don't underestimate the potency of boredom for the Liberals.