Rabbi Dr Jonathan Romain, chair of the Accord Coalition for Inclusive Education and minister of Maidenhead synagogue, writes:

A remarkable new map of how schools in Britain select their pupils shows that the traditional arguments over equality in the education system - grammar and private schools versus comprehensives - miss the hidden unfairness that is secretly going on in the state sector.

Whereas only 5 per cent of secondary-age children attend grammar schools, over three times that number attend state schools that select according to faith, and it is in those schools that a high degree of socio-economic jostling also takes place.

The map - published by the Fair Admissions Campaign - confirms beyond doubt the suspicion often raised but never proved until now: whether by accident or design, religiously-selective admission policies act as a covert means of choosing pupils by ability or wealth.

This is highlighted by the figures surrounding the nationally-recognised marker of children who are eligible for free school meals because of their parents’ low income rates. The maps show some astonishing results; whereas comprehensive secondary schools with no religious character admit 11 per cent more pupils eligible for free school meals than live in their local areas, comprehensive Church of England secondaries admit 10 per cent fewer, Roman Catholic ones admit 24 per cent fewer, Muslim ones 25 per cent fewer and Jewish ones 61 per cent fewer.

No wonder some faith schools do well in league tables, when their intake has been edited to such an extent.

These are extraordinary figures in two other respects. First, there is the massive religious embarrassment that schools whose principles mean that they should be supporting the poor and championing the vulnerable are failing to do so.

Second, it begs the question of why a placement system that was originally designed to protect faith by allowing selection on religious grounds has been so easily hijacked by those seeking to manipulate pupil admissions, be it by the parents or the schools themselves.

A dramatic example of this was seen recently when the London Oratory was criticised by the Schools Adjudicator for breaching the Schools Admissions Code and effectively discriminating against non-Catholics.

The school’s criterion for entry included parents participating in church life for at least three years beforehand through activities such as singing in the choir, serving at the altar or arranging flowers. Such practices should not determine whether children qualify for a place in a state-funded school.

The new map illustrates that the issue is not limited to the London Oratory, but is endemic to the way many other faith schools operate. Spending time in church to gain a school place has become the religious equivalent of paying cash for honours.

It is time to ask why faith schools - unlike other state-funded institutions in society - are allowed a specific exemption from the Equality Act that enables them to choose who they serve on the grounds of belief or practice.

It would be unthinkable for entry to hospitals or libraries to depend on a person’s faith. Schools can still have a faith ethos, but if they are state funded, they should serve their local community without discriminating.

It is also ironic that the very institution - the educational system - that we expect will teach children about values such as fairness and equality actually gives a message of “us and them”, segregating children at the school gates.

The increasing number of faith schools means that there is a real danger of creating educational apartheid, which will not only have a corrosive impact on the children’s outlook, but will then have a divisive effect on society at large.

Our new findings should act as a spur to preventative action. A fair admissions system would be a good start.