The number of charities providing public services rose sharply between 2008 to 2010, according to a £1.5m Cabinet Office survey.
The National Survey of Charities and Social Enterprises is believed to be the largest voluntary sector survey ever conducted, gathering the views of more than 40,000 voluntary organisations.
In the first wave of research conducted in 2008, a poll by Ipsos Mori found that 20 per cent of respondents listed the delivery of public services as one of their roles and 14 per cent said it was their main role.
The figures increased to 31 per cent and 24 per cent respectively in the latest round of research, which was conducted last year.
The number of organisations listing the delivery of other services, such as financial and business services, as one of their roles had also grown from 24 per cent to 34 per cent.
By contrast, the number of organisations operating in community development, advocacy and volunteering had all fallen, albeit by small percentages.
The survey suggested that relationships with councils are improving marginally, with slight increases in the number of respondents who said they felt more valued, respected and understood by local authorities.
Thirty-one per cent identified voluntary income as their most important source of income, compared with 30 per cent in 2008. Nine per cent said grant funding, compared with eight per cent in 2008.
More than 100,000 third sector organisations were invited to participate in the study, which was initially called the National Survey of Third Sector Organisations.
A total of 48,939 did so in 2008, compared with 44,109 last year.
The survey results are broken down nationally and locally.
Nick Hurd, the minister for Civil Society, said he hoped the survey would improve working relationships between the voluntary and public sectors.
"I have written to local authorities encouraging them to explore the results with their local sector," he said.