Jewish education leaders are trying to gauge the knock-on effects of a court ruling that it is unlawful to keep boys and girls apart in a co-educational school.

The Appeal Court said the segregation of the sexes at Al-Hijrah, a state-aided Islamic school in Birmingham which takes children from four to 16, amounted to sex discrimination.

In their judgment, the judges noted “a number of Jewish schools with a particular Orthodox ethos” and some Christian schools follow similar practices.

Rabbi David Meyer, executive director of Partnerships for Jewish Schools (Pajes), the educational division of the Jewish Leadership Council, acknowledged “the decision is potentially very challenging for a number of Jewish schools”.

It was, he said, "very difficult to find an educational argument that can justify the existence of some separate sex schools but render others illegal. Sadly the outcome of this case is likely to be more about limiting parental choice than raising educational standards."

He added, “We are currently evaluating the impact of this decision on our community's schools and will continue to work with the Department for Education in order to ensure that they remain within the law.”

Al-Hijrah was criticised by Ofsted last year for separating boys and girls from the age of 9 for religious reasons.

Although the inspection service found that there was no difference in the educational curriculum, it said both boys and girls were disadvantaged by not being able to socialise with each other.

A High Court judge last year cleared the school of breaching equality law but a panel of three judges, including the Master of the Rolls, Sir Terence Etherton (who is Jewish), upheld Ofsted’s appeal in a judgment published last week.

The issue, they said, whether it was lawful for “a mixed-sex school to have a complete segregation of male and female pupils over a certain age for all lessons, breaks, school clubs and trips”.

Ofsted had made it clear, they observed, it would apply “a consistent approach” to all similarly organised schools if the appeal was successful.

Amanda Spielman, chief executive of Ofsted, said after the judgment, that Al-Hijrah was  “teaching boys and girls entirely separately, making them walk down separate corridors and keeping them apart at all times. This is discrimination and is wrong. It places these boys and girls at a disadvantage for life beyond the classroom and the workplace, and fails to prepare them for life in modern Britain”.

The inspection, she said, would consider the ruling carefully“ to understand how this will affect future inspections.”

The court ruling would seem to apply to schools which prevent any co-educational contact altogether rather, than for example, split them for some religious classes.

One Jewish school that could be affected by the ruling is the Hasmonean High in London which has taught boys and girls on separate sites for more than 50 years, although technically it constitutes a single school.

The school has planned to modernise its girls’ section in Mill Hill and relocate the boys school from Hendon alongside it, while preserving the distinction between them.

“The two campuses would be adjacent to each other, but remaining separate, respecting Hasmonean’s ethos that girls and boys should be educated separately,” the school’s website explains.

Rabbi Jonathan Romain, chairman of the Accord Coalition, which has campaigned for greater restrictions on faith schools, said the Al-Hijrah case "highlights how important it is to for Ofsted to monitor faith schools, so that practices that are illegal or that harm social cohesion are not allowed to exist”.