Labor Party leader Rudd, whom opinion polls are predicting will lose the September 7 poll, said voters were concerned about where billions of dollars in cuts will fall under a conservative government headed by Abbott.
"What people want to hear is, where are you going to cut?" Rudd said at the event in which undecided voters asked questions of both leaders in Brisbane.
"Which jobs, which services, which schools are going to be cut by you?
Abbott accused Rudd of running a scare campaign, admitting a Liberal/National coalition government headed by him would "obviously... Have to find some savings" but insisting that his administration would ultimately make the economy stronger.
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Later when questioned strongly by Rudd on how he would fund his signature paid parental leave policy, the exchange became heated with Abbott turning to the audience to ask: "Will this guy ever shut up?"
Rudd is fighting for his political life in the September 7 poll which opinion polls suggest will see Abbott, a one-time trainee to be a Catholic priest and a former minister in the government of John Howard, elected prime minister.
Labor has pledged its survival on its steerage of the economy during the global financial crisis which kept it out of recession. But after six years the centre-left party's popularity is waning with voters.
Abbott has promised to draw down the budget deficit, and offered a "signature" policy on paid parental leave which would give women up to 26 weeks paid leave at their full wage if they have a baby.
Sky News, which hosted the forum, said the debate was won by Abbott with 37 audience members voting for him compared to 35 for Rudd.
The remaining 33 people in the audience were undecided after the hour-long forum, Sky political editor and forum moderator David Speers tweeted.