Up to 100,000 council jobs could be lost in England as a result of government spending cuts, the Local Government Association has said.
LGA chairman Baroness Eaton said "one in 10 of the workforce" would go.
Chancellor George Osborne cut funding for local authorities by 7.1% from April in Wednesday's spending review.
Ministers say councils can make the savings without hitting frontline services, by "cutting waste, crazy non-jobs and sharing back office services".
The Office for Budgetary Responsibility has estimated 500,000 public sector jobs could go over the next four years, as the chancellor cuts £81bn from public spending.
The LGA has suggested that about 20% of the lost jobs will be in local authorities.
Baroness Eaton dismissed suggestions that some councils would "go bust" but she added: "These cuts will hurt. We know this means there will be fewer libraries, more pot holes going unrepaired, parks shutting earlier and youth clubs closing."
It also meant council workers would face redundancy, she said.
"Some jobs will go in natural wastage, not filling vacancies and voluntary redundancy. But there will be job losses where real people dedicated in their profession won't be there any more."
The government insist that the cuts should not have an impact on frontline services - and local authorities should be able to find ways to cut costs by increasing transparency and sharing services with other councils.
Local government minister Grant Shapps said: "This was a tough but fair settlement. We are giving councils more control over their budgets so they can protect front-line services.
"However in order to achieve this they must cut out the waste and crazy non-jobs, start sharing back office services and join forces to procure to benefit from economies of scale.
"Everyone should do their bit which means bringing senior pay under control and chief execs taking a pay cut."
He told the BBC News Channel: "Until they have done all of these things they shouldn't even be thinking of cutting those frontline services that their residents really need and care about."
He added: "There are lots of reasons why there is a brighter future there, but they must restructure, they must do things more efficiently."