Social care budgets for the elderly in England will be cut this year - despite promises to invest more cash, according to an analysis of spending plans.
The Age UK research, based on freedom of information data, suggested spending on the over-65s would drop by over 8%.
The charity predicted the impact of such a cut could be "devastating" as the system was already at crisis point.
Care services minister Paul Burstow questioned the figures, suggesting the situation was not as bad as claimed.
He acknowledged budgets were "under pressure" but said that did not always lead to a deterioration in care.
"While some councils may simply be cutting care, others are working hard to get more for less with innovative ways of delivering better care, including using more telecare and cutting needless admissions to hospital and residential care," said Mr Burstow.
The findings come after extra money was promised in the 2010 spending review.
Ministers said £2bn more would be invested in social care by 2015, with the first tranche coming this financial year.
This was earmarked for both elderly care and younger adults with disabilities.
The promise came after the government had announced a review of the system amid evidence councils were having to ration care because of the increased demands being placed on services by an ageing population.
That review is due to publish its recommendations next Monday and pave the way for an overhaul of the means-tested system.
Social care has been struggling for funding in recent years with the overall budget only rising slightly above inflation.
In recognition of the problems, the government said last year it would set aside some extra funds to help the system until any new arrangements were introduced.
But the Age UK research suggested that the money was not yet getting through to the frontline of elderly care.
It asked all 152 councils with responsibility for social care for data on their spending plans and service provision for the elderly for this financial year.
The charity received information on spending from 110 councils, which suggested the budget would be cut by 8.4% - equivalent to £610m.
It also received evidence councils were coping by taking measures such as reducing the number of care home places and hours of home help.
Michelle Mitchell, from Age UK, said: "Funding for social care is already inadequate. The consequences of cutting expenditure further could be devastating.
"We are fearful that even more vulnerable older people will be left to struggle alone and in some cases will be put at risk."
Councillor David Rogers, of the Local Government Association (LGA), pointed out while extra money had been promised by ministers for social care, it was being cancelled out by the wider cuts to local government - its budget from central government is being reduced by a quarter over the next four years.
"As the LGA warned last year, and this report backs up, government funding cuts have left councils with huge gaps in their adult social care budgets. Savings have to be found and tough decisions will have to be made in some areas."