A report released this week by the British Humanist Association (BHA) accuses faith schools of failing to comply with admissions regulations.
According to the BHA, a group that often speaks out against religious schooling, a quarter of faith schools investigated were contravening the law and prioritising religion over other criteria such as the prospective pupils' looked-after or financial status.
The report, called An Unholy Mess: How Virtually All Religiously Selective State Schools in England are Breaking the Law, surveyed 70 faith schools, including Jewish schools, in the UK.
A Department for Education spokesperson said: "We want every child to have access to the best education possible, and where there is evidence that a school does not have fair and transparent admissions arrangements, swift action will be taken.