Gordon Brown and David Cameron have clashed over spending cuts, tax and political reform in the first prime ministerial TV debate in the UK.
Brown accused the Tory leader of "airbrushing his policies" and demanded he commit to Labour's spending pledge on the police force.
The Conservative leader accused the prime minister of attempting to "frighten" voters.
Lib Dem leader Nick Clegg said neither of them were being "straight" with voters about the scale of cuts needed.
The audience sat in silence as they addressed questions ranging across the domestic scene, from health and education to tax and spending.
Each leader made a brief opening statement before taking prepared questions from the 200-strong audience.
On the expenses scandal, Brown said he was "shocked" and "sickened" by the revelations.
Cameron described the expenses scandal as a "horrendous episode", saying people "don't pay their taxes for MPs to abuse the system".
But Clegg criticised his counterparts for failing to take action, claiming Liberal Democrat plans for recall powers and reform of party funding had been blocked by the other parties.
Clegg said: "You blocked it. You (Brown) wanted to protect your union paymasters and you (Cameron) wanted to protect Lord Ashcroft in Belize."
However Cameron accused Clegg of taking a "holier than thou" approach on parliamentary standards, highlighting that the Lib Dems had taken 2.5 million pounds from a donor who later went on the run from police.
On immigration, Brown and Clegg both rejected a Tory plan to place a cap on the numbers entering Britain. Cameron said the current system was "out of control".
Sky News will be showing the second debate on Thursday, 22 April, which will look at foreign affairs. The final debate on BBC One on Thursday, 29 April will focus on the economy.
In a poll carried out by ComRes for ITV News of 4,032 voters Clegg was rated the victor, with 43 per cent, against 26 per cent for Cameron and 20 per cent for Brown.
Fullfact.org has examined the claims of all three party leaders, in particular the controversial claims made by Cameron on death rates from cancer in Bulgaria.
Cameron raised a few eyebrows by saying that in Britain "our death rate from cancer is actually worse than Bulgaria's".
Fullfact.org found the latest figures from the World Health Organisation seemed to back the Conservative leader's claims, in its 2009 annual report, the WHO found that on average 147 people died per year from cancer per 100,000 people. This compared to 129 deaths per 100,000 heads in Bulgaria.
