Australian Prime Minister John Howard and his opponent, Labor leader Kevin Rudd, have faced each other in a TV debate as the election approaches.
The debate began politely but grew increasingly bitter
The two sparred over economic policy, climate change and troop levels in Iraq in the live, 90-minute clash.
Both politicians grew more irritable as the debate went on, but the BBC's Nick Bryant in Sydney says neither was able to land a knock-out blow.
Opinion polls put Mr Rudd ahead of the long-serving Mr Howard at present.
During Sunday's debate - the only head-to-head encounter scheduled for the campaign period - the two men clashed over their respective pledges to cut income taxes.
The debate also touched on the issue of climate change - and Mr Howard's opposition to the Kyoto agreement to limit greenhouse-gas emissions.
"How could it be that we're one of the only two developed countries in the world to refuse to ratify the Kyoto Protocol?" Mr Rudd asked.
"I don't understand. I just don't get it."
But Mr Howard said the treaty was flawed because it did not include emerging economic giants India and China or the world's biggest consumer, the US.
"That it doesn't effectively cover the United States and China, that's a bit like having an international world cup in cricket without Australia and India," Mr Howard retorted.
The two also sparred over Mr Rudd's commitment to pull Australian forces out of Iraq by the middle of 2008, even if it damages relations with the Bush administration - a commitment Mr Howard argues will embolden terrorists.
But our correspondent says neither man was able to claim outright victory in the debate.
Current opinion polls suggest Mr Howard, who is seeking a fifth term in office for his Liberal-National coalition, trails his Labor rival by between six and eight percentage points, with five weeks to go before election day.