Cardiff, UK - Sixth form pupils in state schools in Wales are to be given the right to opt out of religious school assemblies.
At the moment they must provide daily collective worship for all children, apart from those withdrawn by their parents.
Similar rules in England were relaxed for pupils aged 16 and over in 2007.
But the Welsh Assembly Government's decision has been condemned by the Union of Welsh Independent Chapels as a "betrayal of Welsh culture".
Under current legislation, maintained schools in England and Wales "must provide a daily act of collective worship which is broadly Christian".
The routine was brought in under the Education Act of 1944.
However, the decision to amend the act has been criticised by the Union of Welsh Independent Chapels.
It said the assembly government was throwing "1,500 years of Welsh Christianity to the wind - at the very time when young people need a sound moral and spiritual dimension in their lives more than ever".
"Over the centuries, Christianity has been the bedrock of Welsh identity and morality," said Dr Geraint Tudur, the union's general secretary.
"This is a secular attack on that Christianity - an act of betrayal by the assembly government. We urge assembly Education Minister Jane Hutt to reconsider."
The Catholic Church in England and Wales has welcomed the decision.
Father John Owen, a spokesman for the church and chaplain of Cardiff University, said: "I have always thought that any form of compulsory worship was counter productive.
"I think it's a personal decision and personally I have no problem with this."
A spokeswoman for the assembly government said at the moment parents could only excuse children from collective worship.
She added: "The Education and Inspection Act 2006 allowed sixth formers in maintained mainstream schools the right to withdraw themselves from collective worship.
"Currently it is only the parent of a child who can make such a request. This change came into force in England in 2007.
"Once the amendment is in force, a parent will continue to be able to request that a child other than a sixth former be excused from collective worship.
"A parent of any child at a school will be able to request that the child be excused from receiving religious education."
It is not clear when the decision will come into force.
• Schools in Scotland are told to provide opportunities for religious observance in school and are encouraged to use Christian resources. In Northern Ireland, schools have to provide collective worship for pupils but a parent can withdraw a child if they want to.