A religious school in east London has failed its third inspection by the education watchdog Ofsted because it did not teach its pupils about sexual orientation.
The watchdog reported that the Orthodox Vishnitz Girls School in Hackney had not given its pupils who are aged up to eight years old, a "full understanding of fundamental British values".
Schools that do not come up to Ofsted's requirements must improve or they could be closed down.
The school charges annual fees of £5,200 and was praised for its resources and teachers' expertise and the report did say that it had improved in safeguarding and leadership, the Telegraph reported.
While acknowledging the school is aware that its policy does not fulfil equality laws, the Ofsted report said the school did not teach pupils "about all the protected characteristics, particularly those relating to gender re-assignment and sexual orientation.
"This means that pupils have a limited understanding of the different lifestyles and partnerships that individuals may choose in present-day society," it said.
This has prompted criticism from Gill Robins, of campaign group Christians in Education, who said in a blog post: "It doesn't matter how good your school is in all other respects – simply refusing to teach very young children about gender reassignment will lead to your closure.
"That is the possible outcome for not only this school, but other Jewish schools which refuse, as a matter of faith, to teach about LGBT issues."
Meanwhile, Jay Harman, educations campaign manager at Humanists UK, told Schools Week, that schools that did not standards should face "proper sanctions".
Six other religious schools had also failed inspections in recent weeks.
The department for education can remove a school from the register, leading to its closure, it fails equality requirements.