The Association of Muslim Schools has failed in a bid to take a legal case on an Islamic faith school's policy of segregating boys and girls to the UK's highest court.
In a landmark ruling last month three Court of Appeal judges found that the policy of the mixed-sex Al-Hijrah school in Birmingham to completely segregate from the age of nine is unlawful sex discrimination.
The judges overturned a High Court finding that Ofsted inspectors were wrong to penalise the school on the basis of an "erroneous" view that the segregation amounted to discrimination.
For religious reasons the voluntary-aided school, which has pupils aged between four and 16, believes that separation of the sexes from year five onwards is obligatory.
The school, which is maintained by Birmingham City Council, has complete segregation from nine to 16 for all lessons, breaks, school clubs and trips.
At the Court of Appeal on Tuesday, the Master of the Rolls Sir Terence Etherton, Lady Justice Gloster and Lord Justice Beatson rejected a move by the Association of Muslim Schools (AMS) to join the legal action.
Ruling on an application made by the association in the wake of the court's October 13 findings, the judges said its purpose was to enable the AMS to apply for permission to appeal to the Supreme Court.
Refusing the application, the judges said the AMS was aware of the proceedings but never applied to join until after the conclusion of the appeal and the making of an order giving effect to the court's decision.