Religious education is being killed off in schools by the English Baccalaureate, RE teachers have warned.
A major new survey on the subject reveals that teacher numbers and GCSE entries have sharply declined and that nearly a quarter of secular state-funded secondaries in England are breaking the law by not providing RE to 14 to 16-year-olds.
The National Association of Teachers of Religious Education (NATRE) is presenting the evidence to ministers to try to persuade them to reverse their decision not to include the subject in the EBac.
At present, history and geography are the only humanities that count towards the GCSE league-table performance measure.
Rosemary Rivett, NATRE executive officer, said: "Within 15 days of the EBac announcement our members were telling us RE was not in a good place."
The association's latest survey, covering RE teachers in more than half of England's state-funded secondaries, reveals that a fifth are flouting the law by not providing RE to key stage 4, rising to 24.3 per cent when religious schools are removed from the results.
The number of law-breakers can be expected to rise in future, teachers said.
The survey found that 28 per cent of secular state-funded schools were planning cuts to RE teacher numbers from September.
RE GCSE entries have dropped in nearly two-fifths of non-religious state secondaries and in more than half of those schools the EBac is being blamed, the survey found.
One teacher said RE had suddenly become "disposable".
A Department for Education spokesman said: "RE remains a vital part of the school curriculum - that's why it remains compulsory for every single student up to 16.
"It's rightly down to schools themselves to judge how it is taught."