Alan Milburn has called for charities to be given a bigger role in the delivery of public services.

In a speech that will be seen as a push for a radical agenda for Labour's third term, the former health secretary said he wants the voluntary sector to "become part of the mainstream of public service delivery".

His comments came in a speech to the Association of Chief Executives of Voluntary Organisations on Thursday.

Milburn believes that Labour has to offer a radical agenda for reform at the next election.

"The job of progressive government today is to provide security and opportunity in an era of almost constant change," he said.

"So the role of the state is not to withdraw, leaving families and communities to the whim of a free market approach, as neo-conservatives on both sides of the Atlantic now seem to believe.

"But nor is it to assume responsibility for everything from the litter on the streets to the behaviour of children in the classroom."

Yet he conceded that there are some boundaries, saying: "Of course there are functions only the state can perform. 

"Defence and security are obvious examples. Immigration and criminal justice are others.

"But when it comes to the provision of other services, such as health or education, they do not need to be exclusively provided by the state."

Public service delivery

Milburn said government should look to the voluntary as well as the private sector when seeking to expand and develop public services.

"The next few years present unrivalled new opportunities for the voluntary sector to expand still further. It offers just the sort of services that are needed today – personally delivered, fairly provided," he said.

"With the right support it can become even more prominent as the government renews itself in office around its core purpose, a future that is fair for all in our country."

The move comes as ministers and senior Labour figures thrash out plans for Labour's next manifesto.

Despite Milburn's radical tone, some ministers are thought to be moving to water down policy in pursuit of what is being dubbed the "safety first" option.

Some reports had suggested the chancellor was mounting a behind the scenes operation to water down the document.

But in an article earlier this week Gordon Brown denied he was shunning radicalism, saying "a new wave of social and economic modernisation and reform is needed".

Any moves to involve the private sector in the mainstream delivery of public services will, however, unease Labour traditionalists.

They fear that public services could be undermined by both greater private and voluntary sector involvement.

The move echoes similar calls from the Conservatives, who have backed moves towards an "enabling state".

But in a warning to the prime minister's critics, Milburn said: "This is not the time to abandon New Labour.

"It is the time to move it forward as we redistribute opportunities in society through reforms that bring more choice, diversity and public involvement in our services."