Unicameral

A unicameral parliament or a unicameral legislature is a parliament or legislature which consists of only one House or Chamber. Most states have two houses, for instance the United States of America, the United Kingdom, the Republic of Ireland, France, Italy and others.

Countries that possess a single chamber parliament or legislature include the People's Republic of China (the National People's Congress), the Republic of China (Taiwan), Sweden, Portugal, and New Zealand. At subnational level, Nebraska in the United States, Queensland in Australia, and all of the provinces in Canada have unicameral legislatures. In the United Kingdom, the devolved Scottish Parliament, National Assembly for Wales and Northern Ireland Assembly are also unicameral.

Many countries with unicameral legislatures are small, unitary states, which consider an upper house second chamber or to be unnecessary, in many instances having abolished the second chamber where one existed. This is either because an elected upper house has duplicated the lower house and obstructed the passing of legislation, or because an appointed or indirectly elected chamber has proven ineffectual. New Zealand abolished its Legislative Council in 1951, Denmark abolished the Landsting in 1953. The functions of reviewing or revising legislation have often passed to parliamentary committees, with further safeguards being a written Constitution.