A judge has barred education regulator Ofsted from publishing a report that found an Islamic school to be inadequate because it segregated girls and boys in what purported to be a mixed school.
The school, which cannot be named, secured an injunction in the summer to prevent the report being published. It was backed by its local authority in bringing the proceedings.
Mr Justice Jay, hearing a judicial review, found Ofsted inspectors wrongly assumed that separation of pupils on the basis of sex meant or implied unequal treatment and that the original report was based on the erroneous view that the school had committed unlawful sex discrimination.
The judge also noted that Ofsted’s rating of the school was based on books offensive to women found in its library, and ineffective safeguarding.
He said: “The present case clearly raises a point of general public importance as to the true construction and application of key provisions in the [Equality Act] 2010.
“It is a point which has not arisen before, and so must be answered on a first principles basis, applying standard interpretative tools to the language, policy and objects of the statute.”
Mr Justice Jay said in his judgment in The Interim Executive Board of X School v Chief Inspector of Education, Children's Services And Skills  EWHC 2813 (Admin) that while the school separated boys and girls it did not treat either less favourably as a result or educate them differently.
“It cannot be said, in my judgment, that one sex is being treated less favourably than the other,” he concluded.
But he did not find that Ofsted acted unfairly or from bias. The school also remains in special measures.
Her Majesty’s chief inspector of schools Sir Michael Wilshaw said: “We are…disappointed that the court has determined that the practice of completely segregating boys and girls in this publicly funded mixed-sex school does not amount to unlawful discrimination.
“I do not believe that segregating children without an educational reason is in their best educational interests."
Sir Michael said Ofsted had gained the judge’s permission to take the matter to appeal.
He said Ofsted had been right to defend the claim brought by the school and its local authority because of the “great public importance” of the issues raised.
“Ofsted is charged with inspecting how well schools are promoting British values,” Sir Michael said.
“In this respect, it was entirely reasonable for inspectors to consider whether a regime that denied boys and girls in a mixed school the opportunity to interact and socialise together was discriminatory and was failing to adequately prepare them for life in modern Britain after they leave school.”