Media playback is unsupported on your device Media caption David Cameron said there was a "fundamental duty" to care for the elderly

Universal benefits for pensioners will once again be protected if the Conservatives win May's general election, David Cameron has said.

Mr Cameron promised at the 2010 election not to introduce means testing for benefits such as bus passes, TV licences and the winter fuel allowance.

In a speech, he repeated that pledge for the next Parliament, "no question".

Labour and the Liberal Democrats have said they would remove some benefits from better-off pensioners.

"In 2010, I looked down the barrel of the camera and made a clear commitment to the British people that I would keep these things," Mr Cameron said.

"And that wasn't a commitment for five years - it was a commitment for as long as I am prime minister."

'Fundamental duty'

Mr Cameron said the payments were not an "unnecessary luxury", and dismissed criticism that pensioners were being unfairly favoured.

He added: "If you've worked hard during your life, saved, paid your taxes, done the right thing, you deserve dignity when you retire.

"These people have fought wars, seen us through recessions - made this the great country it is today.

"They brought us into the world and cared for us, and now it's our turn - our fundamental duty - to care for them."

Analysis by Kevin Peachey, BBC personal finance reporter

This is not the last time we will hear about pensioner benefits - and the claim that they are subsidised by younger generations - during election year.These benefits cost £3bn a year. That is small when you consider that all the main parties are willing to spend hundreds of millions of pounds during the next Parliament by sticking with the "triple lock" protection of the state pension.

So, the debate is perhaps more about the "fairness" of protecting some from cuts, but not others, rather than a merely a matter of finance. The same debate was bubbling around when child benefit entitlement was reduced for more than a million families two years ago. When politicians do their sums about other universal benefits, votes as well as costs will be part of the calculations.

BBC assistant political editor Norman Smith said: "The decision follows the announcement earlier this month by the chancellor that the amount of money set aside for pensioner bonds was to be extended, fuelling claims that the Conservatives are deliberately targeting older voters - because they are more likely to vote."

Universal benefits for older people include free prescriptions and eye tests.

For Labour, shadow work and pensions secretary Rachel Reeves said: "David Cameron's government has let millions of pensioners down, failing to act on rising fuel costs and rip off pension fees and charges."

She added: "As part of our plan to get the deficit down in a fairer way, we will stop paying the winter fuel allowance to the richest five per cent of pensioners and reverse David Cameron's tax cut for millionaires. Accusations that we will end pensioner benefits are simply untrue."

Liberal Democrat Pensions Minister Steve Webb said: "The working age poor will pay the price for the Conservative ring fence for the very wealthiest pensioners."

Mr Webb said the Conservatives were "showing their determination to balance the books solely on the backs of disabled people and the working age poor."