If Legislation is made and it forms part of the school corriculum- WHY and HOW do schools evade it- CAN THEY?

I suppose the answer to your basic question is that schools are regularly inspected by OFSTED. If provision in a certain area is inadequate, OFSTED will report that. A school can get a grade of "satisfactory" even though there are several areas of provision that are inadequate, even if this means that the law is being ignored. OFSTED would probably make it part of the school's action plan and they would look to see if action has been taken at the time of the next inspection.