(CNN) -- Australia's top candidates for prime minister campaigned furiously Friday -- election eve -- as incumbent Julia Gillard was tied with coalition challenger Tony Abbott in a national opinion poll based on the country's complicated preferential voting system.
In Saturday's election, Gillard is the candidate of the left-of-center Labor Party; Abbott represents a conservative coalition.
The Newspoll published Friday morning puts the two political blocs at 50-50.
"People would have seen the polls today and what the polls are telling them is there is a very, very real risk that they will wake up on Sunday and Mr. Abbott will be prime minister," Gillard told the Nine Network's "Today" show Friday morning about the choice facing Australian voters.
"They've got a choice between my positive economic plan to keep investing in jobs, to keep improving schools -- people know I'm passionate about improving education -- to keep improving hospitals and to build the National Broadband Network. Or they can take a very big risk. A very big risk with Mr. Abbott for their futures. It's about work choices for Mr. Abbott. It's about a grocery tax and, of course, it's about going back to the days of cutting schools and hospitals. That's what he stands for."
Noting that Gillard's standing in the polls has eroded in recent days, Abbott said, "I think Labor has found it a bit desperate ... I think they've found it a bit shrill and I just think that they don't have a record to defend and under those circumstances I think they become very negative and very personal and I don't know that that's a good look from a prime minister."
Abbott, a 52-year-old fitness fanatic, said he stayed up all Thursday night and was planning to do the same Friday night in a final push to gain the lead. He appeared at a flower market and a fish market Friday morning.
Gillard, 48 and the nation's first woman prime minister, spent Thursday night in the key southeast state of New South Wales, where she rubbed elbows with voters in a pub and entered a raffle in which she drew her own ticket -- twice.
Gillard served as deputy prime minister under Kevin Rudd when he led the Labor Party back to power in December 2007. But she rose to the top job last June, when the Labor Party unceremoniously dumped Rudd, whose popularity was plummeting -- in part over his stance on how to handle global warming and a proposed system of emissions trading.
Soon after, as she appeared strong in the polls, she called the snap election for Saturday. But Abbott -- who had little national campaign experience -- emerged with surprising effectiveness and broader public appeal than many pundits had anticipated.
The campaign has been marked by negative television advertisements from both sides.
The economy has emerged as a key election issue, despite the fact that Rudd was able to steer Australia away from the worldwide recession that many other Westernized countries have endured. Both candidates tried to persuade the electorate that they will do the best job in reducing the $72 billion deficit.
Gillard has promised a $3.15 billion surplus by 2013; Abbott has promised a surplus of $5.58 billion by then.
Australia has benefited from China's thirst for raw materials -- particularly iron ore and copper exports. Both candidates have said they will quarantine government profits from that.
But tourism and manufacturing have each been struggling, said Michael Stutchbury, the economics editor of the national daily newspaper, The Australian.
Both candidates have plans to expand the availability of broadband internet service, with Gillard promising a system that would serve 93 percent of the population at a cost of $38 billion. Abbott has promised a more modest program, at a more modest price -- $4.5 billion.
The downside of Gillian's plan is that it is expensive, there is no business plan, no cost-benefit analysis, "and the government is really proposing to have a wholesale government monopoly," Stutchbury told CNN.
He described Abbott's plan as "more scaled down, but [offering] more competition."
Regarding what to do about global warming, Gillard has proposed forming a citizens' assembly of 150 people to study the matter. Abbott, who once famously described global warming as "absolute crap," now says he will try to reduce carbon emissions by 5 percent by 2020.
CNN's John Raedler contributed to this story.