Extra funding announced for care services falls "alarmingly short" of the amount needed to meet demand, council directors in England have said.
The Association of Directors of Adult Social Services (ADASS) said the £1bn the chancellor announced for social care was "fragmented" and "short-term".
It said Covid-19 had led to a huge surge in demand for care services.
Councils will get £300m in new money for adult and children's services and be allowed to raise more in tax.
Local authorities will be able to levy an additional adult social care charge on council tax bills of up to 3%, specifically for the care of older and disabled people.
In his Spending Review on Wednesday, Rishi Sunak said these measures would mean councils had access to an extra £1bn to fund social care.
He said this was on top of the additional £1bn social care grant provided by the government this year, which would be maintained into 2021.
ADASS has previously warned of "catastrophic consequences" without immediate investment in the social care sector.
It said councils could run out of cash and care providers could go to the wall, with increased costs due to coronavirus pandemic exacerbating an existing crisis.
In a statement issued on Wednesday, ADASS president James Bullion said the organisation had hoped for a settlement that would have helped it "stabilise" care and support services, as well as greater equality with NHS staff.
"While we are still examining the detail, it seems as if the fragmented short-term funding announced by the chancellor falls alarmingly short," he said.
Mr Bullion said funding was needed to ensure "care providers remain in business, staff are are paid a national care wage that properly rewards them for their amazing work, and carers get the vital breaks they need to keep going".
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