Public ownership is not just a "political decision" but an "economic necessity", John McDonnell is to say today.
The shadow chancellor will say Labour would put democratically owned and managed public services "irreversibly in the hands of workers" so they can "never again be taken away".
Mr McDonnell, who will open Labour's Alternative Models of Ownership conference in London on Saturday, is expected to say: "The next Labour government will put democratically owned and managed public services irreversibly in the hands of workers, and of those who rely on their work.
"We will do this not only because it's right, not only because it's the most efficient way of running them, but also because the most important protection of our public services for the long term is for everyone to have and feel ownership of them.
"We aren't going to take back control of these industries in order to put them into the hands of a remote bureaucracy, but to put them into the hands of all of you - so that they can never again be taken away.
"Public ownership is not just a political decision, it's an economic necessity.
"We'll move away from the failed privatisation model of the past developing new democratic forms of ownership, joining other countries, regions and cities across the world in taking control of our essential services."
Mr McDonnell will announce the creation of a working group to look at how cooperatives can grow, expand, and access capital, and to decide which sectors should be prioritised in the expansion of cooperative ownership.
And he will say the New Economics Foundation (NEF) is producing an independent report, set to be published in the spring, with policy suggestions on how to grow the cooperative sector.
Mr McDonnell will also use the speech to accuse the Conservatives of being "intellectually bankrupt".
He will say: "Under the Tories, Britain is now seriously out of step with our international partners, failing to keep up with them.
"The Conservatives are not just morally bankrupt but intellectually bankrupt: caught between clinging onto the failing dogmas of the past and offering a pale imitation of the radical change which Jeremy Corbyn's Labour Party now offers."
