Ministers this week proposed an amendment to the Education and Inspections Bill saying that 16-year-olds should be given the right to opt out of school prayers for the first time.
Religious education and collective worship is compulsory for all pupils unless parents pull them out. But in a joint statement teachers and religious leaders said the reforms did not go far enough. They said Baha'i schools with non-Christian pupils should be able to stage multi-faith or purely educational assemblies.
"A school community may do many things together but, lacking a shared religion, it cannot worship collectively," said the statement, which was also signed by the Sikh Education Council and the National Spiritual Assembly of the Baha'is.
It added: "In requiring schools to do so, the law is incoherent. On the other hand, good educational assemblies can accomplish much. There is widespread dissatisfaction over the current law and support for its reform."
The six groups backed an amendment to the Education and Inspections Bill, tabled by Baroness Massey and Baroness Turner, the Labour peers, calling for the daily act of worship to be replaced by assemblies which would be "inclusive of all children - the non-religious and those of various religious backgrounds".
The move follows the publication of figures by Ofsted showing that only 17 per cent of secondary schools held broadly Christian assemblies every day in 200405.
Among primaries the figure was 98 per cent. A committee of MPs and peers made separate calls for a reform of the laws surrounding school prayers and RE.
A report by the Joint Committee for Human Rights said the right to withdrawal from worship should be extended to every child, providing they are of "sufficient maturity, understanding and intelligence to make an informed decision", not just those aged 16.
Pupils should also be able to pull out of RE without seeking parental permission first, it said.
Evan Harris, the Liberal Democrat MP member of the joint committee, said:
"It has never been more important for young people to be allowed to choose for themselves what religious beliefs and practice they wish to follow and not be dragooned into worship or directive education by the state"
Lord Adonis, the schools minister, rejected calls for further reform. In a House of Lords debate on Tuesday he said: "Assemblies and collective worship are important elements of school life in establishing their ethos and collective character.
"For those under 16 we believe it right that they should be required to take part unnless their parents specifically wish otherwise."