The Prime Minister - who is marking his first anniversary in No 10 - said that the Government had only just begun to harness the potential of these not-for-profit organisations.

The first step will come with the forthcoming publication of health minister Lord Darzi's Next Stage Review of the National Health Service, which is due out shortly.

Downing Street said that it will include new measures to enable front-line staff working in community health services to opt out of primary care trusts and set up their own, nurse-led organisations.

Writing in the foreword to a Cabinet Office report on public services, Mr Brown insisted that his approach did not mark a return to the days when the poor had to rely on charity for public services.

Nevertheless, the move is likely to alarm the public service unions at a time when they are already at odds with the Government over its determination to hold down public sector pay.

"Building on the success of the foundation trust model in the NHS, which sees a million people actively engaging in the governance of their local hospitals, I believe that over the next decade we will see a growing proportion of our services provided by independent public service providers and social enterprises," Mr Brown wrote.

"We have only just begun to harness the potential for these kinds of non-profit organisations and in the coming weeks we will set out how we can promote a new wave of innovation led by social enterprise whilst protecting the values of publicly funded services free at the point of use.

"Not a return to the most vulnerable in our society depending on charity but a genuine openness to new ways of delivering services to the benefit of all."

The proposals are intended to build on the foundation hospital approach which has been used to give acute services greater independence from Whitehall.