Religious education in schools is "outdated" and needs a massive overhaul to end a "policy muddle" and better reflect modern Britain, according to researchers at Goldsmiths, University of London.
The RE For REal study says that RE is currently a "20th century settlement for a 21st century reality".
It calls for a statutory "national framework for religion and belief learning" and says it should be a compulsory part of the curriculum up to the age of 16 at least.
The report comes a few days after a landmark judgment in the High Court when a judge ruled in favour of the three humanist parents and their children who challenged the Government's relegation of non-religious worldviews in the latest subject content for GCSE Religious Studies.
In his decision, Mr Justice Warby said that the Government had made an "error of law" in leaving non-religious worldviews such as humanism out of the GCSE curriculum, amounting to "a breach of the duty to take care that information or knowledge included in the curriculum is conveyed in a pluralistic manner."
The British Humanist Association, which was responsible for bringing the case, welcomed the decision.