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.
"We will consider the findings of the BHA's report carefully. All of the objections they have listed have now been resolved."