The local leaflets row dates back some months but was one of the flashpoints of the 90-minute prime ministerial debate hosted by Sky in Bristol.
Mr Brown raised the issue when he suggested the Tories had not committed to free prescriptions for the elderly or free eye tests in England - Mr Cameron responded that it was "disgraceful to try and frighten people".
Mr Cameron said a Tory government would keep the free television licence, pension credit, winter fuel allowance and free bus pass and said Labour leaflets suggesting otherwise were "pure and simple lies" and urged Mr Brown to withdraw them.
Mr Brown denied authorising "any leaflets like that" but pointed out that a commitment to keeping free eye tests and free prescriptions was not in the Conservative manifesto. Mr Cameron responded: "Well let me do it right now. We'll keep them."
The row escalated on Friday as the Conservatives accused Labour of spreading "fears and smears" by claiming the Tories would cut free bus passes for pensioners, would scrap free TV licences and the Winter Fuel Allowance.
Tory frontbencher Michael Gove said Mr Brown should apologise to voters who had been subjected to "lies" about the Tories and said Labour had "forfeited the right to govern".
The Conservatives produced 23 leaflets and letter from Labour candidates - some dating from the start of 2010 and one from Mr Brown's parliamentary aide Jon Trickett - which they dismissed as "Labour's shameful lies".
Mr Cameron said: "I'm frankly pretty angry about it because I've seen these leaflets for a long time and they really are appalling... I hope that these leaflets will now be withdrawn."
At a Labour press conference, Mr Brown said: "As a result of panic in the Conservative Party... we now know the Conservatives have changed, their manifesto doesn't say it but they - and I'm prepared to accept this - will now have free eye tests for pensioners."
We moved from "I agree with Nick" to "I disagree with Nick" as Gordon Brown and David Cameron attacked Nick Clegg
But he added: "This has all had to be forced out of the Conservatives."
Business Secretary Lord Mandelson said it was Labour's "duty" to highlight things that were not in the Conservative manifesto: "That is exactly what the prime minister did last night, if David Cameron wants to make policy up on the hoof under pressure as he did - fine. Victory for G Brown, bad night for D Cameron."
Labour's election co-ordinator Douglas Alexander said the leaflets had been produced by "a few" local candidates before the campaign.
Instant polls after the debate, which was watched by four million people according to early over-night figures, gave conflicting verdicts about whether Mr Cameron or Lib Dem leader Nick Clegg came out on top.
A Sky News poll of polls had them tied with an average of 33% against Mr Brown on 27%.
But BBC polling expert David Cowling said there had been a significant drop in the number of people who thought Mr Clegg won, while Mr Brown had the most improved ratings.
Plaid Cymru's Adam Price said the debate had been "undemocratic" - as the Welsh and Scottish nationalist parties had been excluded.
He said the three leaders were "as one" on policies on Afghanistan, pensions, climate change and Trident and there had been "no real debate".
And for the Scottish National Party, Angus Robertson said it was another example of the "cosy consensus" between the three biggest parties and said Scotland was only mentioned once, when Mr Brown talked about the weather.
For UKIP, Nigel Farage said there had been "total agreement" between the big parties on membership of the European Union and without his party's input "we have not had a proper debate about the European Union in this election campaign".
• Conservative leader David Cameron's interview with Jeremy Paxman will be broadcast at 2030 BST on BBC 1.
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