Children at non-faith academy schools are the most likely to be deprived of a minimum level of religious education, a study has found.
The survey, run by the National Association of Teachers of Religious Education (Natre), showed 35 per cent of secular academies failed to meet the legal requirement to offer RE to all students aged 14 to 16.
Exactly a third of community schools also admitted they failed to provide RE at that level, it found.
The figures for older pupils contrast starkly with those for 11 to 14-year-olds, where only 11 per cent of secular academies and 16 per cent of community schools said children missed out.
Natre, which surveyed 580 schools online, said a quarter of all schools are still falling short of their obligations in Years 10 and 11, blaming the introduction of the EBac measure of school performance for the figures.
The study also revealed that the number of qualified RE teachers is declining, with one in five community schools and academies without religious character reporting a reduction in the number of specialist staff.
Natre chairman Ed Pawson said: “Education secretary Michael Gove has admitted that RE has been an ‘unintended casualty of reforms’ and this new data proves his point.
“The EBac has edged RE out of the school curriculum and pupils are losing out on valuable education about the world’s faith and belief systems.
“Good RE is a vital part of a pupil’s whole education. Taught by a specialist, RE reaches beyond class teaching and helps develop skills young people can take into the wider world.
“Yet this research shows that schools are squeezing RE into less time and unfilled timetable slots, often with teachers lacking in adequate training or support. This trend has to be reversed now.”
The latest research follows a report by the All Party Parliamentary Group on Religious Education in March this year, which found that a quarter of schools had made RE teachers redundant or transferred them to other subjects.
Stephen Lloyd MP, the group's chair, said: “Religious education teaches us to understand, question, and see the world from a better informed perspective.
“When RE is diluted, young people leave school ill-prepared to make sense of religion and belief and unable to respond to different views and beliefs in an informed, rational and insightful way.
“It’s vital we work closely with ministers and education officials to ensure RE is not sidelined.”