Would the last nursery school headteacher please remember to turn out the lights?

It is strange to see experts in early childhood education trying to warn of the ill-effects of a new policy initiative, and being treated as if they've got it all wrong.

Early Education is an internationally-renowned organisation, and Jean Ensign is the highly-respected chair of the governing body at Bognor Regis Nursery School and Children's Centre, one of England's very best schools. They are trying to alert the government to problems with the new Early Years Single Funding Formula, which (according to a BBC report) will lead to severe cuts to maintained nursery schools.

School's Minister Vernon Coaker has dismissed their concerns, saying the policy is a matter of "common sense". Given the undoubtedly strong commitment shown to early years education and care by the current government, one can only assume that he has not been fully briefed on this issue.

Far from being simple common-sense, the EYSFF is both highly technical and very complex, and is providing employment to freelance accountants and education policy-makers all round the country as I write, no doubt at a generous hourly rate.

But I think it is fair to say that the EYSFF has two major aims.

One is to fund nursery education by take-up, rather than by available places. In other words, if you are a 51-place nursery school with only 30 children on your roll, you should only get funded for 30 children.

The second aim is to create a "level playing field" in the funding of nursery education and care.

It's this second aim that will cause the problem. Historically, there has been a big difference between state (maintained) nursery schools, and most of the rest of the early years sector. The difference is that the maintained schools employ qualified teachers and have qualified headteachers, too. Teachers are not cheap to employ: the maintained schools are much more costly than their private and voluntary counterparts.

How can the schools justify this extra cost? There are two very telling indicators for the value of maintained nursery schools. The first is that, according to England's most systematic study (the Effective Provision of Pre-School Education, or EPPE Project), nursery schools and centres based around nursery schools with qualified teachers offer by far the most effective early years education. In particular, they provide the most benefit to poorer and more vulnerable children. Children who attend nursery schools and centres based around nursery schools continue to do better than their counterparts all the way through their primary education.

Secondly, Ofsted's Annual Report in 2008 shows that a very high proportion of nursery schools are judged to be outstanding (39%) or good (58%), with none being found unsatisfactory. These are by far the best inspection results in the whole school system.

So, with the EYSFF aiming to create a "level playing field", it seems pretty clear that there are two possible outcomes. The government might put significant additional funds into the private and voluntary sector, in order to enable them to employ staff with the same levels of qualifications as the schools. This is roughly what has happened in Sweden.

Or the government might, in effect, instruct local authorities to redistribute the existing sum of money more evenly across the different sectors.

Given that there is no significant extra money, local authorities are pursuing the second objective. And nursery schools are, understandably, very worried about this. The schools have told Early Education, through a recent survey, that they are anticipating severe budget cuts in the years ahead. Jean Ensign, chair of the governing body at Bognor Regis Nursery School and Children's Centre, worries that "it will decimate what we can do."

In response, Schools Minister Vernon Coaker argues that "the common-sense shift to funding per child from funding per place - where places can currently stand empty and still be state-funded - should not mean a threat of closure, and our pilots this year have demonstrated that."

It looks as if the minister has not been given the full picture by his advisers.

If the EYSFF was just about funding nursery education on participation, rather than on places, then few would argue with him. Some nursery schools hold places empty in case social services need to place children at risk at short notice. But it would not be difficult for the authorities to find a way of funding this emergency provision. If nursery schools are half-empty for no good reason, then of course they should either fill their places, or reduce their size.

But the EYSFF is mostly about creating the "level playing field", and I think it's time that the DCSF listened to groups like Early Education and experts like Jean Ensign and Early Education.

Policies go wrong, and have unintended consequences: no-one expects perfection. For example, the government legislated for a presumption against the closure of nursery schools - yet more nursery schools closed in the decade followng1997 than in any other period, according to figures I obtained on the numbers of nursery schools from 1963 to the present date through a Freedom of Information request to the Department for Children, Schools and Families: (see Nursery School numbers from 1963 to 1997; Nursery School numbers from 1998 to 2007).

There are mountains of studies pointing to evidence that Nursery Schools provide the best early education and the most help to the neediest children and their families. Many local authorities, Islington in London being a prime example, have made a real success of expanding quality early education and care, and have seen how this has benefited children and their families.

But if the DCSF doesn't listen to the possibility they are getting this wrong, then nursery education as we know it now will be finished.