Are you living near a private school? Would you like to use its swimming pool, or rowing lake, or chapel? Do you fancy the idea of your child getting free Latin lessons there? Or can you think of some other way the school could serve the community?

It doesn’t have to be a famous school like Eton or Harrow – you might live near a small one that isn’t a household name. But if you have any good wheezes – Suzi Leather would like to hear from you.

Leather, 51, is the woman at the sharp end of one of the most contentious Labour policies, an attack on the financial basis of private schools that some see as little more than class war.

When the government recently changed the law – scrapping the automatic and historic charitable status of private schools – it delighted leftwingers, who had long asked what on earth was charitable about schools that charge up to £28,000 a year and enable rich children to dominate top universities. Okay, some might have been set up to educate paupers, but that was centuries ago.

From next spring private schools will have to prove they are still charities – by publicly detailing enough good works – if they want to keep their charitable status, which carries with it tax breaks estimated at £100m across the sector.

Leather, as head of the Charity Commission, is the woman leading the organisation that will have to judge whether a school is doing enough to meet the new test.

Sitting behind her desk in the commission’s London offices, she frowns as she explains why the job is so important. “At the end of the day there is a monetary value on charitable status in the form of tax breaks,” she says. “If a charity is unable to demonstrate any public benefit value but is enjoying these tax advantages, the public might well ask: is this a body that deserves this status?”

And that’s why she wants to hear from you. “I am really keen to hear from anyone with views on what private schools could do to justify charitable status,” she says. “There will be a lot of ideas we have not thought of.”

Of course, there’s a lot she has already thought of. This mother of three, who has been dubbed both Sexy Suzi and Quango Queen (this is the third high-profile quango she has chaired in the past decade; she was made a dame in the honours list two years ago) reels off a few suggestions for private schools to digest.

For starters, they could coach state school children in interview techniques to help shoehorn them into universities such as Oxford and Cambridge. “I would like to see the number of state school children going up in top universities,” she says. “This is one way private schools could demonstrate public benefit.”

Then – as many have been rushing to do in recent months – schools could give more places away. Not necessarily to poor children, either, just to ones whose families can’t afford the fees (which must be quite a lot of us).

By now she’s in full flood. “They could allow state schools to use sports, arts or music facilities; they could let state school pupils attend their lessons; they could help set up city academies and they could work with schools overseas.” And if they can’t do any of these, Leather wants private school trustees to “go down the road” and chat to the local state head teacher about “the most useful things to do”.

“This local dialogue will help break down what is quite a separated system of education. To bring these communities together would be good.”

Will the good works have to be worth as much as the tax breaks? “No, I am not expecting an exact equivalence,” she says. “Some activities will be tricky to put a price on.”

But Leather, a Labour party member, has a determined jut to her chin as she spells out the consequences for anyone that fails to measure up.

“If a school is determined not to show any public benefit it cannot be a charity,” she explains. “And the law does not allow a school to walk away from being a charity and take assets with it. We can take those charitable assets and redistribute them.”

True, she adds that she thinks the prospect is “vanishingly rare”. Nonetheless, even a fleeting image of the rolling acres of one of our famous schools being “redistributed” is shocking.

“This is not about class war; it’s about maintaining the integrity of charitable status,” she insists.

The government’s move on charities may have delighted leftwingers but it has infuriated and terrified many private schools. The Independent Schools Council has already warned that it may mount legal challenges to the commission’s guidelines. (“I’m confident our legal reasoning is sound,” retorts Leather.)

Paul Easterbook, head of the 220-strong prep school Hatherop Castle, near Cirencester in Gloucestershire, is so worried he breaks off from a croissant-making trip with a class of 11-year-olds in France to spell out his anxieties. “Yes, we are concerned,” he says. “We were set up to further education. That was enough of a charitable purpose when we started [in 1926]. But now we are going to be swamped with large demanding annual returns in which we will have to provide a lot of information to the Charity Commission and on which it will judge us.

“Our fees are our income. That is it. It all comes off the bottom line for us.”

From an income of £1.5m, the school already provides subsidised places worth £40,000. “We have looked at Farm Africa and we support the local church.” But he’s not sure whether they will be seen to be doing enough.

“We are aware there are going to be demands on us and if we cannot meet them we have 220 little lives in our hands. We know what we are doing we do well; we get good results and turn out all-rounders. Not to be able to carry on would be a travesty. But if we can’t meet the commission’s requirements it will be a problem.”

Isn’t Leather perturbed by such stories and by the risk that some schools may have to raise fees to hard-pressed parents to pay for change?

After all, she was herself educated for a while at a private school and still has a daughter at a fee-paying school in Devon, which she declines to name. “It does lots of charitable works” is all she will give away.

“We are not saying that schools have to ask parents to pay more. We are giving a range of ways schools can do this,” she says. But she does reveal that she has ruled herself out of final decision-taking about whether an individual school is allowed to remain a charity because she feels that her daughter’s position creates a potential “conflict of interest”.

After a few more weeks of consultation, in July the commission will issue its final guidelines to schools. Next spring they will have to set out their charitable activities alongside the value of their tax breaks.

“I think that for some this will be the first time schools have seriously sat down and thought, okay, what is it that we do do?” says Leather. She pauses. “I think it will be of considerable interest to the public.”

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