Politicians find it all too easy to make policy on the hoof, failing to think through the repercussions of their decisions - and regret and U-turns normally follow double-quick.

The aftermath of the annual Budget bunfight often throws up an example or two: think of the furore surrounding the “pasty tax” from a few years ago. Red faces all round.

Too often policies emerge as if they’d been cooked up the night before, which all too often they have.

There are more than a few educationists who worry that such decision-making resulted in the bulk of the content of the notorious education Green Paper published before Christmas, with its evidence-lite approach to the reintroduction of grammar schools across the country.

The question is, however, whether this is also true of the document’s approach to the independent school sector?

It must have seemed relatively easy in the weeks that followed Theresa May’s elevation in the aftermath of last summer’s Brexit carcrash for her team of advisers to throw together a series of crowd-pleasing education policies. Ones designed especially to delight the new demographic du jour, the Just-About Managings.

Forcing the independent sector to increase its engagement with the state sector - by either sponsoring a new academy or offering a much larger proportion of bursaries - must have seemed a quick win, especially since fees have rocketed to such a degree that the sector’s biggest public schools - those that organise themselves into the HMC - have lost many of their instinctive supporters in the middle classes.

The Green Paper is explicit: the independent sector must do as it is told or the government will either use either the levers of charitable status - by reforming the rules so that the financial benefits are withdrawn if schools don’t bend to the government’s will - or completely new legislation to make them play ball.

Setting to one side the fact that the track record of what happens when a big independent school attempts to run a state comprehensive is patchy at best, it’s easy to see the political attractions of such a policy: force the toffs down from their ivory towers - or duff ‘em up.

It looked like an easy political win: “What could the independents say in response?” (without looking like they’re elitist snobs unwilling to share their toys), May’s brain trust must have asked themselves. (In a similar vein last week, former education secretary Michael Gove used his Times column to give the sector a right good bashing, calling for the withdrawal of its tax benefits.)

Crossing the red line

I fear the government has underestimated what the Green Paper proposals mean to the sector. This easy-to-sell bit of policiticking represents a very real red line to independent schools.

The clue is in the word “independent”. The sector is deeply worried that the proposals found in the Green Paper represent a profound erosion of their independence. As one senior figure in the sector put it to me, “agreeing that the education secretary can tell us what to do effectively makes us accountable to the government for the first time”.

There is very real horror at this proposal. It is a rubicon the independent sector will fight tooth and nail to see uncrossed. Heads and educationists worry that accepting such an idea would open the floodgates. Hundreds of years of independence - in some cases, thousands - would suddenly be gone. 

It is this very independence, they say, that has been the driver of their internationally renowned success - the DNA of which successive governments have been so keen to clone in the state sector.

As it stands, there are high-level conversations going on with ministers in which I understand the sector’s representatives are making this case forcefully.

They argue - not without at least some justification - that they already do much in the way of work with the state sector, sharing resources, facilities, teachers, and, in some cases, even sponsoring academies. They would even like to do more, especially in teacher training, and hope to do so in the future. This, they argue, is because it is the right thing to do and they happily volunteer such time and money.

They cheerfully point out that collaboration in education is nearly always most successful when voluntary, as against when schools are forced together. “How would maintained comprehensives react to being mandated into a partnership with a local public school?” they ask. But as it stands, independents are very angry about being ordered to do it. It is something, they say, they will not stand for. 

At this point in negotiations, while we await the results of the Green Paper’s consultation, the sector’s representatives believe their strongest weapon in this row is the strength of their argument. They hope to see off the potential erosion of their independence with persuasion.

But if these arguments fall on deaf ears? What next?

Actually, the sector is fairly relaxed about changes to charity law: the legislation is complex in the extreme and the sector is far from convinced the government can bend it sufficiently to its will.

And fresh legislation?

Perhaps counter-intuitively, one sector leader told me, with unmistakable mettle in his voice, that he was prepared to tell them to legislate and get on with it. Why so bullish?

One reason is that legislation allows the sector to threaten the deployment of an ultimate sanction.

Certainly not all schools would be prepared to take part, but this makes it clear that if the government legislates to force independent schools to work with their maintained sector cousins in specific ways, that is exactly what they will do: but little else.

Legislation would allow schools to restrict their partnership work to the minimum set out by law: and much work with other schools, for example helping with teacher supply in Stem subjects, could end. When criticised, they would argue that they are simply acting in the interests of their charitable trusts, the remit of which does not normally extend to partnership work or outreach.

This is not a matter of schools warning that they will take away their toys in a huff, but rather making the point that if you coerce them into spending money on projects they wouldn’t otherwise choose to do and don’t believe are educationally sensible, then their other stuff - which doesn’t fall within the strict confines of their trusts’ remits - will likely be shelved.

No doubt the sector’s representatives would reject the comparison to a trade union work-to-rule campaign; but there is very real danger of a withdrawal of goodwill.

That the sector is even prepared to consider such a controversial strategy demonstrates the extent to which it feels its independence is under attack.

Ed Dorrell is head of content at TES. He tweets @Ed_Dorrell

Want to keep up with the latest education news and opinion? Follow TES on Twitter and like TES on Facebook