The oldest and poorest UK pensioners are suffering from inflation rates double that of non-pensioners, it was claimed on Thursday.
According to the Institute for Fiscal Studies (IFS), the most impoverished pensioners have an average inflation rate of nine per cent, compared to 5.4 per cent for non-pensioners.
This is due to the fact pensioners spend a greater percentage of their income on energy and food - both of which have seen massive price rises in recent months.
Louise Ward-Bergeman, incomes policy officer for Help the Aged, said: "Pensioners living on low fixed incomes with little hope of pulling themselves out of financial difficulty are even more likely to feel the pinch.
"With prices for essential items going up and up, many older people are forced to cut back further and further, watching their quality of life deteriorate before their very eyes."
She added 2.5 million pensioners live in poverty and 1.4 million live in deep poverty.
"It's high time the Government took the bull by the horns and ensured older people get all the benefits they're entitled to," Ms Ward-Bergeman said.
"More than £5 billion goes unclaimed each year, lining the pockets of the Treasury instead of helping older people who, in the face of sky-rocketing inflation, need it just to get by."
The Liberal Democrats say the figures prove that pensioners are struggling to make ends meet under Labour.
"They are falling further and further behind the rest of the population, hit hardest by rising fuel and food costs," the party's work and pensions spokesperson, Jenny Willott, said.
"This year's rise in pensioner poverty will not be a one-off unless ministers increase the state pension and ensure more people claim the pension credit to which they are entitled," Ms Willott continued.
"Around 1.8 million pensioners who were eligible for pension credit did not claim last year, missing out on an average of £1,543 over the year."
According to government statistics, the number of pensioners living in poverty increased by 300,000 last year, while pensioner couples have a total pension income of £10,000.
The Lib Dems claim that the majority of pensioners are unaware of the pension credit eligibility rules and in what circumstances it is claimable.
The party also says that the government is doing little to motivate applications for state pensions, with a target to increase the number of people claiming pensions to 3.2 million dropped last year.