none of the above. Unless you have power of attourney, noone can make a decision to refuse or accept medical intervention on behalf of another adult in this country. In reality, the doctors will take everyone's opinions into account but will do what is in "the best interests" of the patient. However, they are not bound by the decisions the family come to. There have been several cases where family have disagreed with doctors and have had to take it to court to get a ruling. If someone in the family strongly disagrees the doctors may take legal advice. does your wife have any mental capacity now to be able to say what she wants in the future?