The government has confirmed that public health funding is likely to be around £4bn, but has delayed shifting responsibility for local public health spending to councils until at least April 2013.

Under plans set out in the public healthwhite paper this week, a new body called Public Health England will sit within the Department of Health to oversee the new system.

The body will be formed through a merger of the Health Protection Agency and the National Treatment Agency for Substance Misuse. PHE will have a ““strong local presence” in the form of Health Protection Units which will work with the NHS and local government across local authority boundaries to co-ordinate health protection, the white paper says.

However it insists these will be organised to achieve “maximum efficiency rather than the present mandated regional structure”.

But, while PHE will be created in April 2012, the public health service will only be fully in place “from 2013”, in contrast with an earlier deadline of April 2012.

This means ring fenced budgets for councils will also arrive a year late, although they will be published in shadow form in 2012-13.

Speaking at the launch on Tuesday, health secretary Andrew Lansley said: “I’m absolutely clear we need a stronger public health strategy…People’s health and wellbeing will be at the heart of everything local councils do. It’s nonsense to think that health can be tackled on its own.”

Councils and commissioners will have to wait until the outcome of a consultation ending next March before the full details of funding arrangements, including the allocation formula for determining ring fenced budgets, are released.

The consultation will also decide the formula for a new health “premium”, under which disadvantaged areas will receive a relatively bigger increase if they improve health outcomes.

There remains substantial uncertainty over how much is actually spent on public health and how the functions are defined.

The £4bn figure referred to in the white paper appears to be based on a 2009 estimate by Health England that public health spending equated to roughly 4 per cent of the NHS budget in 2006-07.

However Audit Commission analysis earlier this year showed that around 62 per cent of that spending was determined centrally, for example through core funding to the HPA and centrally mandated immunisation and screening programmes.

Despite the uncertainty, NHS Central Lancashire director of public health Maggi Morris welcomed the introduction of ringfenced budgets and plans for local authorities and Public Health England to appoint local health directors.

However she warned against restricting the numbers of directors. The white paper says the role “can be shared with other local councils if agreed locally.”

Ms Morris said: “It’s a very big, complex job. I wonder in real terms whether [combined roles] are doable given the size of the populations.”

The main aim of the white paper is to “nudge” people towards healthier lifestyles, for example by handing out prizes to children who walk to school.

Work will be carried out with the food industry to encourage people to eat more fruit and vegetables through a public health responsibility deal, to be published in early 2011.

Mr Lansley will sit as chairman of a new Public Health Cabinet Committee, in order to improve cross government working.

An impact assessment published alongside the white paper says Mr Lansley will require a public health service that “he is able to deploy flexibly as needs arise and change.”

Shadow health secretary John Healey said Mr Lansley’s white paper “fell short of his own hype.”

He said: “As a former councillor, I welcome public health coming home to local authorities but this is happening at a time when councils are facing unprecedented cuts. And it is doubtful whether public health funds can be ringfenced when local authorities are making cuts of up to 30 per cent.”