BOYS chasing places at the London Oratory attended by Tony Blair's sons had better make sure that any brothers and sisters already at the school toe the line.
From next September the over-subscribed school is to use the performance of siblings as one of its admissions criteria.
Pupils have to show a commitment to the ethos of the school where head John McIntosh insists parents observe the three Hs - haircuts, holidays and homework - and be practising Catholics.
New arrangements for admission to the school obtained by The TES show that brothers and sisters must also now have a satisfactory record. This means they must have consistently achieved A or B gradesfor effort in all subjects, general attitude to school, work and conduct.
And they will also need to have been punctual, not skipped lessons and to have taken part in extra-curricular activities or made a contribution to the school in another way.
The Oratory - attended by Euan and Nicky Blair - each year admits 160 11-year-old boys to the first form, and 50 16-year-old boys and girls for A and AS-level courses. There are also specialist music places for 20 seven-year-olds.
Priority is given to practising Catholics, and the school interviews parents to ensure their children are suitable. Written evidence is also obtained from parish priests.
No one has objected to the arrangements. Last year there were 21 appeals but all failed.
Martin Rogers from The Education Network, a local authority-funded information service, said the rules appeared to defy both the spirit and letter of the new admissions code. He added: "It will be a shame if they have not been challenged.
"They are neither clear nor objective, as required, so cannot be fair. Parents failing to get a place at the school for their child in the coming admissions round would be well advised to appeal."
The network will now be auditing this year's admissions arrangements, in order to identifying those disregarding the code of practice.
Mr McIntosh said: "The code of practice says denominational schools can interview parents to determine whether they agree to the ethos of the school as part of their religious commitment."