Public health is a new burden – it’s official. And local authorities are right to be nervous.

The provisions brought in by Labour are meant to recognise the full costs of services or responsibilities that fall to local government and cover them for hidden costs, but local authorities are right to be nervous. The sums don’t stack up or square with Andrew Lansley’s aspiration for a new, groundbreaking service.

The £4bn spoken of in the public health white paper sounds substantial, but it is less than 4 per cent of the current NHS budget, less than it holds back for contingency purposes, and less than we pay out for inflation. It is a pathetic amount. Surveys suggest the public thinks the NHS spends about 30 per cent of its budget on prevention.

The £4bn figure is based on the last full year of NHS financial data, from 2006-07. That was a bad year for public health, because its budgets were raided to bail out the first payment by results funding disaster. So it’s a very poor position to start from.

Neither did the list of public health services in that £4bn include the National Treatment Agency, the public health observatories or strategic health authority and government offices. Nor did it include sexual assault referral centres, never before funded by the NHS.

But, most crucially, that sum does not include overheads. That omission alone could add 15-25 per cent to the bill, but some local authorities will want 30 per cent and universities, of course, would ask for 40 per cent.

Public health could work from home with no HR, finance or IT support and not get paid. And not have support services such as public information and press communications, which are a vital part of what we currently get from primary care trusts. Public health also gets a share of PCTs’ commissioning expertise, rarely separated out of the corporate resource. These specific omissions from the returns the directors of public health made to the Department of Health budget exercise – based on the NHS North West pilot last autumn – leave public health well short of viability.

The health secretary wants a ringfenced budget, protected from plunder. He seeks the added protection of an outcomes deal and a health premium reflecting major health needs and rewarding progress. But it is a budget based on the health service’s historic failure to fund preventive care – by definition, therefore, inadequate and bound to fail. A ringfenced budget of nothing is still nothing.

In the past, I said we needed 5 per cent for public health, but that is just for starters. The eventual sum will need to be 10 per cent, 20 per cent, or even the 30 per cent the public wrongly thinks we currently spend.

Once you get past the budget and calculation, you arrive at the allocation process. Whenever any couple separates, the family treasures never quite add up. The NHS is no different. Some will remember the National Treatment Agency for Substance Misuse being set up. Health authorities made returns on the substance use budgets – generally including alcohol – but we only saw funding back for drugs. We then had to refinance alcohol service budgets.

When the Health Protection Agency came along, we again declared our funding for health protection into the national budget. We have all had to rebuild our local health protection resource to cover things the HPA failed to do – like sexually transmitted diseases, healthcare acquired infections, tuberculosis and pandemic flu. Now we face the same again; an assumption that anything spent on health protection is in the national pot for Public Health England. That could put our local staff and a vital resource for public protection at risk.

Some local authorities have been eyeing the funding to cover budget shortfalls, but they will need a lot more than that to cover the 27 per cent cuts they are enduring. In any case, the new burden brings a new responsibility: which is more important, saving lives or saving money?

The health premium, the outcomes framework and the expectations of Public Health England will require health improvement for the money. Public health directors in local authorities will need to call on other local budgets and cut deals with GPs to get better outcomes to attract more resources. Public health has saved the NHS money and can do so for the local authority. But it requires a lot more intelligence.

The government needs to make the ringfence big enough to make a difference, £4bn won’t even help. Public health won’t survive on £4bn.