The Accord Coalition says that the problem with schools admissions is not just one of people cheating, but of policies which themselves discriminate, especially on grounds of religion or belief.
Accord, which campaigns for inclusive education, was responding to reports that the Schools Adjudicator will be seeking new penalties for parents who break school admissions rules.
The chair of Accord, Rabbi Dr Jonathan Romain, commented: “The unfortunate reality is that religious admissions requirements encourage deceit and hypocrisy while punishing the conscientious."
He went on: "In this sense it is not the 'cheats' who are the problem, it is the system. Schools can never tell how religious a family really is and instead have to rely on easily manipulated tests like church attendance. This means that atheists desperate for a place at a particular school will be prioritised above Christian families who prefer to worship at home."
"The truth is that both children and society would be best served by a system that prohibits religious segregation and adopts a more inclusive approach," said Dr Romain.
At present, faith-foundation schools are allowed by law to discriminate on religious grounds in admissions and employment policies, even though they are mostly or wholly funded by the general taxpayer.
Campaigners for reform of faith schools say that this is unfair and inappropriate.
The Accord Coalition has brought together an unprecedented alliance of religious believers, humanists and others to argue for change.
The Christian think-tank Ekklesia, the Association of Teachers and Lecturers and the British Humanist Association are among the corporate founding members of Accord - whose individual sponsors also include leading Christian clergy, rabbis, secularists, members of others religious traditions, academics, educationists, scientists and writers.
Accord Coalition: http://www.accordcoalition.org.uk/