Governors of a Roman Catholic school attended by two of Tony Blair's sons have won the right to continue interviewing future pupils and parents.
The school is heavily over-subscribed
England's Schools Adjudicator last October imposed a ban on interviews as part of the admission procedure.
Dr Elizabeth Passmore argued they were not "necessary or desirable" in the light of current admission practices.
But on Friday the school won the case on grounds that the ban could undermine its "essential Catholic ethos".
A new code of practice on school admissions says that, in future, the only schools that may retain interviews of parents and children are boarding schools for a boarding place.
'Cheating in writing'
But at the High Court in London on Friday, Mr Justice Jackson found the governors had made "a formidable case" for retaining interviews.
"It is perfectly possible to have regard to a provision but not to follow that provision in a particular situation," he said.
The school, based in Fulham, west London, is heavily over-subscribed.
Interviewing applicants helped ensure successful candidates were truly committed Catholics, Charles Bear QC argued on behalf of the Oratory.
Applications completed by parents or parish priests were often unreliable as parents could be willing to go to extreme lengths to ensure their children won a place, he added.
The judge refused the adjudicator permission to appeal against his decision, partly due to the fact that the admission process for the academic year 2005-06 needs to be completed by 24 January.
The school was founded by the Fathers of the London Oratory in 1863.