The impact on the voluntary sector of today's comprehensive spending review will be "particularly severe", according to the law firm Withers.
Chris Priestley, partner in Withers’ charities and not-for-profit team, said: "Public sector cuts could transform Britain’s not-for-profit sector beyond recognition."
Some charities, he said, faced "dramatic and perhaps fatal cuts in funding streams", while others could benefit from the big society programme.
"What we are seeing already, and what we expect to see much more of, is novel approaches to finding alternative sources of funding, such as social impact bonds and the under-used community interest tax relief," he said.
"In addition, trustees of grant-making trusts and foundations should brace themselves for an unprecedented wave of appeals for replacement funding."