NHS, 'Consent to treatment' (last reviewed 29/3/19)
Consent guidance These three linked web pages are entitled: (1) Overview; (2) Assessing capacity; and (3) Children and young people.
The "Assessing capacity page" states: "Situations that must always be referred to the courts include: ... withdrawal of nutrition and hydration from a person who's in a permanent vegetative state or minimally conscious state."
However, in NHS Trust v Y  UKSC 46 the Supreme Court stated:
The question that arises in this appeal is whether a court order must always be obtained before clinically assisted nutrition and hydration, which is keeping alive a person with a prolonged disorder of consciousness, can be withdrawn, or whether, in some circumstances, this can occur without court involvement. ... In conclusion, having looked at the issue in its wider context as well as from a narrower legal perspective, I do not consider that it has been established that the common law or the ECHR, in combination or separately, give rise to the mandatory requirement, for which the Official Solicitor contends, to involve the court to decide upon the best interests of every patient with a prolonged disorder of consciousness before CANH can be withdrawn. If the provisions of the MCA 2005 are followed and the relevant guidance observed, and if there is agreement upon what is in the best interests of the patient, the patient may be treated in accordance with that agreement without application to the court. I would therefore dismiss the appeal. In so doing, however, I would emphasise that, although application to court is not necessary in every case, there will undoubtedly be cases in which an application will be required (or desirable) because of the particular circumstances that appertain, and there should be no reticence about involving the court in such cases.