An extra £100 a month for the over-75s is at the heart of Liberal Democrat proposals for pensioners.
Elderly people are much more likely to vote than young adults
They are promising a "citizen's pension", free personal care for the elderly, and to replace the council tax in an effort to win over the elderly.
Leader Charles Kennedy said it was "time to treat older citizens fairly".
The Tories promise council tax rebates for over-65s and better pensions. Labour is planning reforms of both pensions and the council tax.
A Help the Aged survey suggested 73% of over-65s were certain to vote, and many were considering switching allegiances in the run-up to the general election, widely predicted to be called for 5 May.
Mr Kennedy confirmed a package of measures which he said was worth £6.7 billion more than Labour's plans.
Among them was the promise of an extra £100 a month for single pensioners over 75 and more than £140 a month extra for pensioner couples over 75.
Free personal care for the elderly in England, to match that offered by the Labour-Liberal Democrat coalition in Scotland, free off-peak local bus travel for pensioners and scrapping the retirement age were among other measures.
And the party says its plans to replace council tax with a local income tax would help pensioners, many of whom are on low incomes but live homes with high council tax bills.
The measures would cost £3bn a year, which the Lib Dems say they will find by re-prioritising £5bn of existing government spending.
Mr Kennedy said: "Our message to older citizens is that we recognise our debt to you. You have worked long and hard to build up our country. It is time to treat older citizens fairly. It is time for a real alternative approach."
But the government accused the Lib Dems of offering "false promises" to pensioners and said their plans would create a "huge black hole" in public finances.
Work and Pensions Secretary Alan Johnson said: "Like the Tories, the Lib Dems have no clue as to how they would pay for their pensions commitments."
A recent MORI survey of 1,948 adults for Help the Aged found 26% of the over-65s were prepared to change their mind about which party to support.
It suggests there could be as many of 1.76m potential "floating voters".
And according to the survey, 73% of over-65s said they were "absolutely certain" to vote, compared with 34% of those aged 18 to 34.