Mark Lehain is the founder and principal of Bedford Free School.

Let’s consider the scene at the Department for Education.

In the recent General Election you were badly affected by the most successful union-coordinated campaign in living memory – that around school funding. It doesn’t matter that much of what was said in this campaign was misleading or hyperbolic, it had traction. People trust teachers more than politicians, and when Heads wrote home to blame the government for school cuts, parents listened. This probably feels harsh, especially as school funding was protected in real terms until very recently, and you’re moving to a fairer National Funding Formula which everyone agrees is a good thing, albeit in need of cash to protect those losing out from it.

I really don’t envy Justine Greening and her team right now. It could and should have been so different. Education since 2010 has been a Conservative success story. As well as protecting spending until recently, teacher pensions were reformed in a way that kept them extremely generous but made them more affordable.

Teachers and schools have been given greater freedom, so they can spend more time doing what they think is best for their students and less on centrally-directed fads. To support this autonomy, the DfE set up an independent body, the Education Endowment Fund, specifically to enable proper, valid research to be conducted, assessed and disseminated.  The National Curriculum and exams system were reformed to make them more rigorous. Ofsted was reined in and forced to work with the profession, not antagonise it.

Education secretaries also challenged the vested interests that were holding people back, such as those found in Local Authorities, and addressed some massive wastes of money, like as the Building Schools for the Future scheme. Oh, and of course, the massively successful and popular Free Schools programme was kicked off, to provide more school places and innovation across the country.

And yet today the Education Secretary is facing pressure from all angles, including a union movement re-energised by the funding campaign success. So I’m not surprised that people are reviewing every aspect of education spending to see what can be saved, but I was taken aback yesterday to see a front page story in The Times about the Free School programme potentially being slashed and the money put into the general school budget. Doing this would be short-sighted, would undermine standards, and would be very, very un-conservative.

It would be short-sighted because the vast majority of Free Schools are set up simply to ensure that there are enough places for the rapidly growing number of children in the country.

Between 2016 and 2020 it is estimated that the school population will increase by around 460,000. We can’t simply rely on existing schools expanding, as they’ve already done so massively, creating 444,000 places since 2009. Many schools simply have no room to expand further, and there comes a point where they are too big to effectively support their students.

So if we have rapidly growing demand for school places, and existing schools can’t provide all the additional capacity, then we need new schools – which is where Free Schools come in. (And they are a much more cost-effective way of doing it than what we had before 2010, being 29 per cent cheaper per square metre than Labour’s Building Schools for the Future scheme.)

That’s why cutting Free Schools would be short-sighted. It would also damage the progress we’ve made in raising standards in schools in recent years – and in this regard I don’t just mean in terms of exam results or Ofsted judgements.

At its simplest, the Free Schools policy is just a way of lowering the barriers to entry in our school system, allowing schools to spring up where the demand exists. It keeps existing schools on their toes, and has enabled people to innovate, trying completely different approaches to education, and open such variety up to people who would otherwise have been denied it as they couldn’t afford higher house prices or private school fees.

The policy has enabled the opening of insanely successful schools as different as Dixons Trinity Academy, West London Free School Primary, Reach Academy Feltham, Tauheedul Islam Boys’ High School, School 21, The Boxing Academy and, of course, Michaela Community School.

These schools, and others, have shown what can be done when teachers and parents take control of education for their community. They’ve piloted methods to transform student culture, reduce teacher workload, and raise educational aspirations in previously low-performing areas. Why would we slow down or stop a programme with such a burgeoning record of success?

Finally, Free Schools are a most quintessentially conservative policy: they transfer power from politicians to people, increase choice and diversity for all, and provide a ladder for social mobility up which children and their families can climb.

It’s probably why they are so popular with the communities they’re based in. While the naysayers claimed they wouldn’t be well received, the opposite has proved to be the case, with secondary Free Schools typically much more oversubscribed than equivalent Local Authority schools.

My own school, Bedford Free School, opened in a town with some surplus places and facing massive political opposition, but is now significantly oversubscribed in every year group, and we’ve been approved to open a second in nearby St Neots due to overwhelming parental demand for what we’re offering.

Any attempt to save money through downgrading this policy would be a false economy. Perhaps more perniciously, a U-turn here would signal a return to the bad old days of “other peoples’ children”, where those in power, influence and money deny choices to others that they themselves have access to.

I know for a fact that Greening, Theresa May, and others don’t believe that; indeed, that they are driven by the very opposite. And that is why they need to shut down immediately any idea of scrapping a policy so perfectly suited to benefit those most in need.