The poll showing that most parents report that their child's school is not obeying the law to provide "daily collective worship wholly or mainly of a broadly Christian character" (which is what, incredibly, the law still requires) should come as no surprise. The last time Ofsted inspected it, it found the same thing, and the head of Ofsted at the time spoke out for a repeal of the requirement. He was not alone. Parents' groups, religious groups (apart from the Roman Catholic and Anglican churches) and many others, including every major teaching union, have called for reform in the past 13 years since the requirement was last reconfirmed in 1998. The requirement for collective worship was one of the most popular proposals for a law to be scrapped on the Your Freedom website launched by deputy prime minister Nick Clegg and it is currently one of the most popular education petitions on the new government e-petition website.

What would replace the law is not difficult to determine. All around the country teachers and headteachers who are breaking the law are providing excellent assemblies, free of compulsory worship. These assemblies typically use stories or music from a range of different sources to explore shared values, build community, and enrich children's moral and cultural development. A requirement to provide assemblies of this sort whether on a class basis or a whole school basis would be a worthy successor to the current hangover from 1944.

But the fact that the law is not being observed obscures the strongest reason for repealing it, which is that in some schools – and primary schools in particular – it unfortunately is being observed. Weekly requests for help and advice from parents related to worship in their child's school constitute the largest single category of advice requests received at the British Humanist Association.

In one dramatic case, a seven-year-old girl was so traumatised by stories of hell and God's wrath that she became, in her mother's words, "a fearful and anxious child". A request that her daughter be withdrawn from worship that involved Bible stories containing violence (which were presented as true) was ignored. Not all children would have such a strong reaction, but the parent in question accurately observed that non-religious stories involving the same level of violence would – quite rightly – not have been allowed.

In another case, one teacher told pupils that involvement in worship meant they were Christians whether they liked it or not. Apart from being a violation of a child's right to freedom of conscience, this created a very difficult situation in the home for the parent of one child who contacted us, who found it difficult to explain why his child should usually believe his teacher but on this occasion his teacher was wrong.

More shocking are the frequent cases where outside evangelical groups are brought in to run assemblies – something that the explicitly religious nature of the legal requirement to provide worship obviously encourages. We have cases where outside visiting speakers tell "true stories" of healing miracles or divine retribution. One assembly was treated to the assertion from an outside speaker that there were "good arguments on both sides" for whether dinosaurs lived at the same time as human beings.

The fact that a law is not being observed can be a good reason for its repeal – but so too can be the fact that it is being observed all too scrupulously.