MPs are to quiz private school heads as independent schools are placed under pressure to justify their charitable status.
The Charities Commission today published a report warning charities cannot be "exclusive clubs" as the public benefit is "very limited" if only a few people can join or access their services.
This places pressure on independent schools to show how they help children that cannot afford to attend them or risk losing their £100 million tax break.
The Commons children, schools and families committee now plans to scrutinise the commission's guidance.
Committee chairman Barry Sheerman told the Guardian: "I want to see a rigorous scrutiny of what the charitable work of each of these schools is and the ways they will work to justify that charitable status."
It will hear evidence from public school heads and representatives from the commission.