The survey found that 38 per cent of respondents had volunteered formally – defined as unpaid help through groups and organisations – at least once in the 12 months before the interview. The figure was 44 per cent in 2005 and has fallen steadily since then.
In the poll of 10,000 adults in England and Wales, 24 per cent of respondents said they had volunteered formally at least once a month between April and September 2010. The figure was 29 per cent in 2005.
The year-on-year fall has been mirrored in informal volunteering - defined as unpaid help for individuals who are not relatives. For the most recent period, 54 per cent said they had volunteered informally at least once in the past year, and 27 per cent said they had done so in the past month.
This was down from a peak of 68 and 37 per cent respectively in 2005.
Joe Saxton, co-founder of consultancy nfpSynergy, said that the figures were disappointing in the light of the government’s level of investment in volunteering over recent years.
"It shows that this investment in volunteering hasn’t produced the goods," he said. "Why are we continuing to shove money into something we can’t demonstrate works?"
The government’s recently published Giving Green Paper emphasises that volunteering plays an important role in society. The paper proposed a volunteering match fund worth £10m a year and a volunteering infrastructure programme worth £42.5m over four years.
A Cabinet Office spokesman agreed that the figures in the survey demonstrated that "simply throwing money at volunteering doesn’t work".
He said: "We’re taking a fresh approach, dealing with the red tape that puts people off and building a big society where it will be normal for everyone to get involved."
"This is backed by targeted programmes, such as the National Citizen Service, community organisers and the Volunteering Infrastructure Fund. If people have other good ideas they should let us know through the Giving Green Paper consultation."