Your quotation from the circular is accurate but incomplete. The sentence you quote relates to the previous two, which say: "Where the circumstances are such as to lead the teacher to believe that the pupil has embarked upon, or is contemplating, a course of conduct which is likely to place him or her at moral or physical risk or in breach of the law, theteacher has a general responsibility to ensure that the pupil is aware of the implications and is urged to seek advice (from parents and health service professionals). In such circumstances, the teacher should inform the headteacher."
The circular is, therefore, requiring both the teacher and the headteacher to make judgments about the circumstances which the pupil has revealed to them and then to encourage or urge the pupil to confide in his or her parents and health service professionals.
No teacher or head would have any difficulty with the concepts of physical risk or breach of the law, where these are clearly indicated, but the moral questions are often more complicated.
A teacher or head may well be persuaded that the pupil would be at physical risk at the hands of the parents, were the circumstances to be communicated to them.
They might also take the view that, whatever their own moral judgment may be, the pupil has already reached the point where seeking advice from health service professionals may actually reduce the risks to which he or she is exposed, rather than increase it.
In any event, they are called upon, by their vocation as well as by the circular, to exercise their best professional judgment in the interests of the child and that judgment may well be that the wishes of the pupil should be respected.
They will place a value on the confidence which the pupil has placed in the teacher and they will reflect on the fact that a departmental circular conveys guidance rather than legal requirements.
They may also recall that this particular circular was written in the time of a Secretary of State for Education whose attempts to impose his own stern moral views were not matched by an understanding of reality as it is confronted daily by many teachers. Unless and until a court rules otherwise, teachers and heads may adhere to the Children Act.