The Office for Civil Society’s total spending is expected to fall from £192m in the current financial year to £74m in 2014/15, according to the Cabinet Office’s annual report and accounts.
The accounts, which were published last week, show that departmental spending at the OCS peaked at £227m in 2009/10.
It fell to £192m in 2010/11 and will remain at that figure this year. Spending is forecast to fall to £146m in 2012/13, £82m in 2013/14 and £74m in 2014/15.
This represents a 61 per cent decline in three years, which is higher than most other government departments.
The OCS’s administration budget is also expected to shrink from £4m this year to £3m in 2014/15, when the next spending period ends.
The department’s main programme cost in 2010/11 was the youth volunteering charity v, which received £47.3m, the accounts show.
An OCS spokeswoman said: "Civil society cannot be immune from reductions in spending."
She said the sum allocated over the current spending period "shows our support in the light of very tight finances".
The higher budgets in 2011/12 and 2012/13 were largely due to the £100m Transition Fund and the pilot stages of the National Citizen Service, she said.
Roberta Blackman-Woods, the shadow minister for civil society, said she was concerned by the figures.
"Cuts of this nature might hinder the delivery of the big society programme and suggest that the government is not fully committed to investing in the voluntary and community sector in the long term," she said.