In UK state (public) schools, christian worship is a legal requirement, as is the teaching of religion - emphasizing christianity. Parents have a legal right to opt their children out but that right is not widely known and some headteachers have been known to deny it even exists.
When I qwas at school, several of my classmates and I were severely beaten by the christian religious education/indoctrination teacher for daring to say we didn't believe in her god.