Many countries with unicameral legislatures are unitary states, which consider an upper house or second chamber 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, like the Landsting in Denmark (abolished in 1953), or because an appointed chamber has proven ineffectual, like the Legislative Council in New Zealand, (abolished in 1951). Unicameralists argue that the functions of a second chamber, such as reviewing or revising legislation, can be performed by parliamentary committees, while further constitutional safeguards can be provided by a written Constitution.
Examples of single chamber parliaments or legislatures include:
In the United Kingdom, the devolved Scottish Parliament, National Assembly for Wales and Northern Ireland Assembly are also unicameral.
See also: Bicameralism, List of national legislatures