Assaults against healthcare staff have gained increasing attention, prompting the Zero Tolerance Zone campaign in the National Health Service (NHS) (Department of Health, 1999). This advised that treatment could be withheld as a sanction, although not from ‘anyone who is mentally ill or under the influence of drugs'. More recently the NHS Security Management Service (Department of Health, 2005) found that the greatest number of assaults (over 43 000) were found in mental health and learning disability environments.