Co-operatives, mutuals and social enterprises would all help to create a more balanced and mixed economy and bring innovative and imaginative business ideas, said the election document.
Under the Liberal Democrats, Northern Rock would be turned into a building society and community-owned energy schemes would be encouraged.
A Mutuals, Co-operatives and Social Enterprises Bill would also be introduced to bring the law up to date and give responsibility for mutuals to a specific minister.
It also said it would split Royal Mail, by handing over the Post Office into full public ownership and the postal delivery part of the business would, in-part, be handed to employees.
In response to the manifesto, David Coulter, Deputy Chief Executive of Co-operatives UK, said: "We welcome the fact that the manifesto – uniquely among the three main Westminster parties – commits to a new Mutuals, Co-operatives and Social Enterprises Bill to bring the law up to date and give responsibility for mutuals to a specific minister.
"We also welcome the commitment to a level playing field for co-operatives in the tendering process for services within health, thus ending any current bias in favour of private providers.
"The Liberal Democrat manifesto outlines their belief ‘that mutuals, co-operatives and social enterprises have an important role to play in the creation of a more balanced and mixed economy’ and this is a sentiment we endorse."
Added Co-operative Party General Secretary Michael Stephenson: "This just shows how far apart the parties are on a new agenda for Britain’s future. Their policies are vague and hopeful and, like the Tories, it is clear they have little understanding of the values of mutuality and co-operation and how they can be used to deal with the major challenges of the day."