Nearly a quarter of people in their early 50s polled by Age UK are afraid of falling on hard times and being forced out of their homes.
The charity says 23% of the 971 people they asked aged between 50 and 55 fear that they will not be able to keep up mortgage payments or rent.
Age UK says that people in this age group should be at the peak of their earning power.
But instead, it says, they are beset with financial worries.
"We know that times are tough financially," said Michelle Mitchell of Age UK.
"But when a significant number of people aged 50 and over say they are worried about losing their homes, it's a clear sign that many are truly struggling to keep their heads above water," she said.
Age UK said the figures painted a "worrying picture" of tomorrow's pensioners.
It said those in their early 50s were more likely to be made redundant than younger workers, and it was harder for them to get back into the workplace.
Peter Owen, from Ulverston in Cumbria, is in his early 50's, and lost his job in education when two schools merged.
He has found work again, but it is much lower paid.
As a result he could no longer afford to keep up mortgage payments.
"My wife and I have had to sell our house and now live in rented accommodation," he told the BBC.
"All planning for future generations is on hold," he said.
Anita Hunt, a housing adviser from Lincolnshire, says she's seeing increasing numbers of people over 50 who are struggling financially.
"Many have worked since leaving school and are expected to continue until almost 70," she said.
"Wages are effectively dropping, or they are out of work for the first time ever due to redundancy or ill health, and are floundering," she told the BBC.
Those who have already retired have been hit by falling savings rates.
Anyone with a private pension will also have found annuity rates at a historic low.
Annuities are used to provide people with an annual income.
Since April 2012, the annual income, or annuity, from a £100,000 pension pot has fallen by £433, according to Age UK.
But there was better news for those over 60 in a recent report from the Institute for Fiscal Studies (IFS), which suggested that those aged 60 or more had seen their incomes rise since 2008.
It argued that poverty in old age was being reduced and that pensioners had seen larger rises in their income than any other age group.