Britain’s equality watchdog has weighed into the JFS court case, arguing that it should remain unlawful for Jewish schools to select children on the basis of whether their parents are Jewish.

The Equality and Human Rights Commission told the Supreme Court this week that it considered using parental descent to decide admissions as racial discrimination.

The commission “considers that all rules based on a person’s descent from a particular class of persons are properly considered to be racial rules,” it stated in a written submission to the court.

It said that the Court of Appeal was right to rule against JFS in summer.

JFS has appealed against the Appeal Court decision, arguing that its entry policy was religiously, not racially, based.

The nine Supreme Court justices have now retired to consider their judgment and are expected to issue it before the end of the year.

As well as the Equality Commission, the British Humanist Association also backed the case against JFS.

But interventions from the Board of Deputies and the Government both challenged the Appeal Court ruling.