One of the most frustrating aspects of the government’s response to the £3 billion funding crisis in schools is its refusal to accept that cuts of this magnitude will have really serious consequences on the quality of education.

In January, Department for Education bosses were called before Parliament’s Public Accounts Committee (PAC) to provide evidence on the financial sustainability of schools. They avoided questions on the real-world impact of cuts and instead quoted national headline figures and talked about “the average school”.

I have yet to visit an average school. Hearing from government that the average school has a surplus of £120,000 will do nothing to help the headteacher of a school facing a deficit this year. Knowing that the Department for Education’s teacher supply model predicts 8,000 more teachers nationally by 2020 does nothing to help the headteacher who has no choice other than to lay off staff. Being told that, nationally, £1 billion efficiency savings are “doable” through better procurement is of no help to the headteacher who has already realised these savings yet still can’t balance the books.

Averages calculated from headline figures are a poor basis on which to set or justify savings targets. The DfE cannot possibly know how its cuts will play out in individual contexts and circumstances. Schools which, on the face of it, appear alike may well have considerably different capacity to achieve savings, due to factors such as the experience and cost of staff.

‘Schools will have to lose staff’

The DfE’s solution? To share with headteachers facing financial difficulty examples of schools “similar to their own” with excellent performance and lower costs. It is difficult to see how this strategy will be of much use to anyone. If my car is broken down by the side of the road, showing me a picture of a car that works is not going to help me.

When it comes to the impact on outcomes, the government appears to be blinded to the simple truth that schools are only as good as the people who work in them. If you want great teaching then you need great teachers who are continually developing their skills. To make savings of the order proposed, schools will have to lose staff and cut training budgets to the bone. School leaders might well find themselves increasingly “firefighting” as the staff-team is stretched to breaking point, distracting them from actually leading the school. The logic is inescapable - school leaders will find it harder, and in some cases impossible, to deliver the same pace of improvement in standards as in recent years.

The government needs to act or we will see the quality of education suffer. Education must be seen as an investment in this country’s future and not just a burden on the Treasury. As Anne Marie Morris MP put it to the permanent secretary at the PAC meeting:

“I would certainly like - and I suspect most schools and parents would like - some assurance that what you are doing now is not going to detrimentally affect the quality of the education that these children are getting. Nothing you have said to me so far has given me any comfort.”

Nick Brook is deputy general secretary of the NAHT school leaders’ union. He tweets as @nick_brook

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