The Education Secretary Gillian Keegan is to say later this week that gender ideology is a ‘contested belief’ rather than a fact if it comes up in lessons.

The intervention comes after widespread concern about teaching in RSE (Relationships and Sex Education) classes, including claims that some pupils had been taught there could be as many as 72 genders.

Schools will not be obliged to teach about gender ideology (the belief that gender is more important than biological sex) but if they do, they cannot present it as fact, and must present ‘gender-critical’ beliefs as well.

The new guidance from the Department of Education will also instruct schools to show all their materials to parents.

The Conservative MP Miriam Cates said: “For too long activist groups have been pushing a politically motivated agenda on children under the cover of RSHE.

“The Cass Review shows how dangerous it is to let ideology overtake facts. We need compulsory guidance to restore common sense and the rights of parents to know what their children are being taught.”

The Prime Minister’s official spokesman has commented: “The PM ordered a review of the guidance on RSHE teaching in schools, following concerns that inappropriate content was being taught.

“We believe parents have a fundamental right to see materials being used in these lessons and the Education Secretary also made that clear when she wrote to parents in October last year.

“The review…will build on this, making sure that children are always taught sensitive content in an appropriate way.

“However, what I would say is we have been consistent that the idea that someone can have a gender identity different from their sex is a contested political belief that must not be taught as fact in our schools.”