The question a judge has to ask in deciding whether or not life-sustaining treatment should be withdrawn is whether the continued treatment is lawful. It will be lawful if it is in the patient’s best interests. Identifying this question gives no guidance about how to approach the assessment of best interests. It merely identifies the judge’s job. The presumption in favour of the maintenance of life is part of the job that follows the identification of the question.
The presumption is best regarded as a presumption of law. It has long been recognised as part of the way in which the English law discharges its obligations under Article 2 of the European Convention on Human Rights (the right to life). But even if it is a ‘mere’ evidential presumption it cannot, on the facts of most cases involving applications for the withdrawal of life-sustaining treatment from patients in prolonged disorders of consciousness, be rebutted.