Laura McInerney is battling with the education department for the right to know how it decides which new schools to approve

I never intended to involve the lawyers. Really, I didn't. I made a simple request for information from the Department for Education, expecting they would just hand it over. But, rather than release it, Michael Gove, the education secretary, has told MPs he will do "everything possible" to stop me getting it. In the coming months, his department is taking the Information Commissioner – and me – to a tribunal in an attempt to block its release under the Freedom of Information Act.

This whole saga started 15 months ago, when I submitted what I thought was a simple request for information to the DfE. What explosive material did I want? A surprisingly dry package: the application forms sent in by people applying to run free schools, and the letters later sent back explaining whether or not they were successful. Hardly the Pentagon Papers.

To say I am surprised the DfE is behaving in this way is an understatement. I thought the request was a no-brainer.

For the uninitiated, the free schools policy, introduced in 2010, allows any group of people to apply to the DfE for funding to open a state school. The government talked at the time about the policy's prior successes in America and Sweden, but the lesson of the American experience is that some US states do it well and some do it badly. To further research the topic, I took a break from my job as a secondary teacher, and in August 2012 accepted a Fulbright scholarship to study at the University of Missouri.

It quickly became apparent to me that implementation matters – and the application process is critical. If taxpayer money is being handed out to members of the public, we need the government to be savvy about which groups they back and why.

So I decided to ask for the applications and the basis of the government's choices – a process that is otherwise entirely opaque. Prior to 2010, the opening of new schools was far more transparent. The reasons for accepting or rejecting all new school bids were routinely published on the Schools Adjudicator website. Local authorities published school bid information when running new school competitions. Naively, I assumed the government would maintain this level of openness.

The information, however, was nowhere to be found.

I therefore asked for it from the DfE, using the Freedom of Information Act. The act is not well known, but it embeds in law the presumption that information held by public authorities is open to anyone who asks for it, unless there is a specific reason not to disclose. And, usually, even if there are reasons why the government would prefer not to give the information, those reasons must be balanced against public interest. As I saw it, if this sort of information had been available before, why not now?

Yet the DfE rejected my request – twice. Among the reasons given was that releasing the information "would allow opponents of free school applications to attack applications more easily and could undermine local support". But why shouldn't the public know about any issues with the applications? It is our money paying for the schools and our children walking into them. It also claimed the amount of information released would be "overwhelming". Given that the department trusted me to teach people's children, I'm fairly certain I can handle reading some application forms.

Nevertheless, the department disagreed. When a public authority turns down a request even after you have appealed to it, you can then appeal – free – to the Information Commissioner's Office, an independent authority whose job it is to uphold information rights.

I was reluctant to go down this route, but was encouraged by FOI campaigners. As one pointed out: "A response is not a favour to be granted, it is a legal obligation. You are a member of the public, and you are paying their wages. You have a right to the information." In the past 15 months, I have repeated this point to myself time and again.

Getting an ICO judgment was not quick, but their officers were extremely helpful. My case worker constantly and professionally explained the legal oddities and remained upbeat. Yet each time there was progress, the DfE would raise a new point – dragging the whole process on for months.

In July 2013, I was finally told the ICO was near a decision. Nothing. By September, the draft notice was apparently ready. Still nothing. In October, I wrote asking for an update. Nearly there. By mid-November, I had practically given up when an email from the ICO dropped into my inbox.

I had won, and then some.

Figuring it out was not easy. Flicking through the 17-page judgment, written in legalese, I struggled to understand what it meant, but the following line made it all worthwhile: "The Commissioner considers that the public interest factors in favour of the disclosure of the withheld information are very strong."

This was not a half-hearted judgment. The ICO argued that the case for disclosure was "very strong" and it would provide "considerable information about the implementation of a relatively new and very important education policy".

The news was timely, arriving hot on the heels of troubling free school developments. Al-Madinah free school's Ofsted report labelled it "dysfunctional" and inadequate in every category. King's Science academy in Bradford is being investigated for fraud. Discovery New School, Crawley, is considered so problematic that it must close before the end of the academic year.

And these free schools have been no small cost to the taxpayer. A recent National Audit Office report price the policy at over £1.1bn. Of this, more than £700,000 was spent on schools that passed the application stage but never opened, and £241m went on schools that opened in areas with lots of spare local school places. The NAO report also noted that some high-scoring free-school applications were rejected, but some low-scoring ones were accepted. Why? On what basis? No answer is given.

How can the public be sure ministers weren't waving through applications from their mates and turning down those whose faces didn't fit? We can't. Without the applications being public, there is no way of knowing if the process was corrupt, or not.

Also, school applicants must include evidence of local "demand" or "need" for their proposed school, usually gathered during a required local consultation. But how can residents know that the reported results of the consultations are fair? There is nothing to stop applicants from writing that everyone was positive at the event even if the exact opposite is true.

Of course, amid this mess some free schools are doing marvellously. I recently visited Greenwich free school, one of the most over-subscribed schools launched under the policy. I was impressed with the teaching, and the pupils, and I spent time discussing with school leaders how the school might continue being great. In fact, it is precisely because I want free schools to be great that transparency is so important.

No one benefits by having applications locked in a dusty vault. In fact, in the US, supporters of the policy – such as the National Alliance for Public Charter Schools – actively press for total transparency around the process. In this country it would build public support, prevent cronyism and allow prospective applicants in areas with huge primary school place shortages to learn from the best applications and improve their chance of getting the school they need.

And so I ended 2013 much as I finished 2012 – sitting down, for the second New Year's Eve in a row, to write an appeal against the DfE's counterproductive desire for secrecy. This one, however, will be sent to a judge in the First-tier Tribunal, who will hear the case brought by the DfE against the ICO and me. These courts are designed with lay people in mind, and no legal aid is available, so I am likely to be representing myself.

Surrounded by highlighters, guidance documents and notes, I veer between feeling like Erin Brockovich [the US activist – played by Julia Roberts in a movie – who fought an energy company over contaminated water] and a 12-year-old trying my best with a history project. Still, parents, teachers, pupils and local residents deserve absolute openness in the operation of our schools. I plan to do everything possible to make sure they get it. After all, as I have told myself for the millionth time, transparency is a right – not a favour.

The tribunal is expected in summer. Education Guardian will follow Laura McInerney's progress