The new Mental Health Act for England and Wales is likely to extend the powers of mental health review tribunals (MHRTs) by giving tribunals the power to approve all compulsory treatment (Department of Health, 1999a, b). The medical member may be dropped entirely from the tribunal's proceedings (Richardson & Machin, 2000). In Ireland, a proposed new Mental Health Act will introduce MHRTs for the first time (Calvert, 2000). The 1983 Mental Health Act contains no explicit statement of underlying principles, although some were introduced in the revised Code of Practice. The Expert Committee (Department of Health, 1999b) suggested that the new Act should specify broad principles where these would help in statutory interpretation, particularly because a range of practitioners working in different settings will be required to understand and implement its provisions. The Green Paper initially suggested that the proper place for setting out principles should be a Code of Practice, but ended by inviting comments on the principles proposed by the Expert Committee, and on whether inclusion of principles would aid interpretation of the new Act.