Last month the chairman of the Church of England's Board of Education, the Bishop of Ripon, suggested that a wider definition of worship would include many pupils and teachers excluded by the traditional format.
Now he has been joined by the Churches' Joint Education Policy Committee, representing Anglicans, Roman Catholics, the free and black-led churches, the Orthodox churches and the Society of Friends (Quakers).
It warns that "irrelevant or hypocritical" collective worship could prejudice pupils against Christianity and other faiths.
"Worship in county schools is distinctive in that the school community is drawn from homesparents with widely differing views of the purpose of existence," says a statement sent to the Department for Education. "It is therefore a 'collective' not a 'corpus' and its worship must span and meet a range of experience, presuppositions and perceptions."
The Joint Policy Committee says that collective worship provides an opportunity for moral and spiritual growth, for developing the community feeling in a school, and for exploring ideas of belief and value. But collective worship should not assume that pupils will engage in Christian practices, nor is it an opportunity to introduce them to other religious traditions. Pupils must be allowed to respond individually.
The statement points to the widespread professional concern about the law which says that schools must provide daily acts of broadly Christian worship. A survey by the National Association of Head Teachers found that 69 per cent of schools were unable to fulfil this requirement.
Such concerns were acknowledged last month when the Church of England announced its own investigation into the issue, and suggested it might recommend changes in the law.
The Church's Policy Committee points to possible legal changes, such as changing "daily" to something less frequent, or changing "collective worship" to "collective assembly". However as a change in the law is unlikely, the statement suggests improving the existing law.