A leaked report claims the charity sector is facing local and national government funding cuts of between £1bn and £5.5bn, it was reported.
The report was compiled by an umbrella organisation, the Association of Chief Executives of Voluntary Organisations (Acevo), which helped run the £100 million transition fund set up by the Government to aid charities facing financial difficulties.
Acevo found applicants to the fund faced cuts of more than £520 million in the current financial year and estimated the whole UK charity sector faced cuts of between £1 billion and £5.5 billion, the BBC said.
The report was said to have been leaked by the Labour Party.
According to the Observer newspaper, charities in the north-west and north-east of England are over-represented in the group of organisations which have asked for help from the fund.
Quoting the report, it said 450 organisations in the 20 most deprived areas have lost £142.5 million.
This is compared with a £3.6 million loss for 22 organisations in the 20 least deprived areas.
A Cabinet Office spokesman told the newspaper the report was a "misrepresentation" as it was only based on applicants to the fund.