Trusts have been given the go-ahead to draw up their own policies on when treatment should be withheld from patients on the grounds of unacceptable behaviour.Verbal abuse, threats, destruction of property and drug or alcohol abuse in hospital, as well as actual violence, can mean that a patient can be denied NHS treatment as part of the government's 'zero tolerance' campaign.Those with severe mental health problems or life-threatening conditions cannot be refused treatment.The Royal College of Nursing said nurses would find it difficult to refuse treatment to a patient, but the guidelines made it clear that dealing with violence should not be a part of a nurse's job.The British Medical Association supports the move, but said there would be 'ethical and practical difficulties' in withdrawing care in accident and emergency departments.