Anger at banks
In heated exchanges, Cameron said: "Our economy is stuck in a rut and we need change to get it moving."
"Shrink the economy now as the Conservatives want to and they risk your jobs and living standards," Brown argued.
The issue of the country's spiralling public debt has dominated the election campaign, which comes as Britain shows signs of a feeble recovery from recession.
Widespread anger at bonuses paid to bankers, who were bailed out with taxpayers' money during the financial crisis, meant that the leaders also spent time discussing how best to regulate banks.
Brown said that Labour would not allow banks the freedoms they enjoyed - many voters would say abused - in the past.
"I will say to these bankers we will never allow them to act in an irresponsible and unfair way again," he said.
Cameron said the banking crisis was "completely unacceptable" and promised to "grip it very, very hard."
"We want to see banks lending again, particularly to small businesses," he said.
Dr Andrew Hilton, director of the Centre for the Study of Financial Innovation, told Al Jazeera that there is little agreement between the parties on how to get out of the financial black hole facing the UK.
"There's no consensus. Do you cut hard and fast, or do you wait as long as you can? The UK economy is not in great shape and it's quite possible we could kick the UK back into recession if we get this wrong. The situation is very serious."
Brown went into the debate in the knowledge that his performance could make or break his party's hopes of clinging to power.
He endured torrid 24 hours leading up to the debate after being unwittingly recorded deriding a pensioner who had questioned him on immigration.
The story dominated the media in the run-up to the debate, which was widely seen as one of Brown's last chances to turn his electoral fortunes around.
A poll published after the debate found that David Cameron was perceived to have won by a narrow margin.
The ComRes polling company said that 35 per cent of viewers believed the Conservative leader had won the debate, while 33 per cent gave victory to Nick Clegg.
Gordon Brown was seen as the clear loser, with only 26 per cent of the vote.
Daniel Hamilton, a pollster from ComRes, told Al Jazeera that the results will be "very concerning" for Brown and his team.
"There's been no movement back to Labour," he said. "If the polls are to be believed, then this a significant sea-change in British politics."
The US-style televised debates have proven hugely influential in the campaign.
The Liberal Democrats unexpectedly surged in the polls following strong performances from Clegg.
After decades of being regarded as a minor force in British politics, the party is now consistently beating Labour in opinion polls.
With just a week left in the race for Downing Street, polling figures suggest the country is headed for a hung parliament, where no party wins a parliamentary majority.