The Big Lottery Fund should fund social enterprise as well as the traditional voluntary sector, the Social Enterprise Coalition's general election manifesto is expected to say.
The manifesto, which is due to be published on Easter Monday, will argue that lottery money targeted at the voluntary sector should also support social enterprises that deliver significant public benefit, such as the Community Initiative Partnership that maintains the Redlees Studios art gallery in Isleworth.
It is also expected to push for tax relief for social enterprises outside the sector that provide "substantial, quantifiable public benefit".
Andrea Westall, deputy director of the New Economics Foundation, said: "Charities don't have a monopoly on public benefit. Many social enterprises make important economic and environmental contributions to society. Any significant impact should be recognised in tax relief and access to appropriate funding."
Child, health and social care are areas in which the coalition believes social enterprises can play a larger role.
The manifesto is also expected to call for political parties to introduce a community 'right to buy' derelict or underused land or buildings that can be converted for a social purpose.
And it is likely to urge the next government to set up social venture capital funds that invest in social enterprise. They would set terms that were appropriate for businesses prioritising social and environmental returns.
Jonathan Bland, the coalition's chief executive, said: "The three main parties recognise the importance of social enterprise. But they need to push it higher up their list of priorities."
He added that the coalition wanted to explore the issue of tax relief for social enterprise with the Treasury, along with the extension of tax incentives for investment in social enterprises that are not limited to deprived areas.