Frail old people in England are being left to fend for themselves because government-funded care is being scaled back, a review suggests.
The number of over-65s being helped by councils had fallen by a quarter in the four years to 2014, the joint King's Fund and Nuffield Trust report said.
This was despite more people needing help, because of the ageing population.
Ministers said they were taking measures to address the problems.
But the report goes on to highlight the growing numbers left with no care or having to pay for support themselves.
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The report has been released on the day the BBC publishes an online guide to care, which details the costs people face wherever they live in the UK.
Care is means-tested, with only the poorest getting help to pay for services, including help in the home for daily tasks such as washing and dressing, as well as round-the-clock support in care homes and nursing homes.
The think tanks carried out interviews with people working in the service and being cared for, as well as analysing existing data during their review.
The numbers getting help from their council with care had fallen by 26% to 850,000 in the four years to 2014
Spending on care by councils had fallen by 25% in real terms in the five years to 2015, to £5.1bn
Additional money from the NHS and increased contributions from individuals had topped this up to £7.2bn, but that still represented a cut of 9%
Over 40% of money paid to care homes came from people paying for themselves
One million people with care needs now receive no formal or informal help - a rise of 10% in a year
The report also warned that the cuts by councils were a risk to the future of the market.
It said it was only a matter of time before a care provider - most services are provided by outside agencies - collapsed, and it noted that providers had walked away from council contracts in 59 local authority areas.
Bruce Moore, chief executive of Housing and Care, a large home care provider which is looking to sell the contracts it has, said councils had driven down fees so much he could no longer recruit and retain the staff he needed.
"The local authority market is really under pressure at the moment."
The review said such pressures were likely to continue, claiming the funding outlook for the coming years was "bleak" and ministers needed to reform the system or be honest with the public that government-funded care was extremely limited.
But the government said it was investing in the care system.
A £5bn pot of money has been set aside to encourage joint work between the NHS and care sector, with an additional £1.5bn being added to that by 2019, and councils have been allowed to increase council tax by 2% a year to invest in care services.
A Department of Health official added: "We understand the social care system is under pressure, and this government is committed to ensuring those in old age throughout the country can get affordable and dignified care."
Ray James, of the Association of Directors of Adult Social Services, said councils simply did not have enough money.
"We're now at a tipping point where social care is in jeopardy," he said.
"Unless the government addresses the chronic underfunding of the sector, there will be worrying consequences."
Caroline Abrahams, of Age UK, said: "Social care is in serious trouble, and this is putting the health and dignity of today's older people at risk.
"Today's reports highlight the need for serious reform to a system that is being starved of the cash and the attention that it deserves."