In government, unicameralism (Latin uni, one + camera, chamber) is the practice of having one legislative or parliamentary chamber. Thus, a unicameral parliament or unicameral legislature is a legislature which consists of one chamber or house.


Unicameral legislatures exist when there is no widely perceived need for multicameralism. Many multicameral legislatures were created to give separate voices to different sectors of society. Multiple chambers allowed for guaranteed representation of different social classes (as in the Parliament of the United Kingdom or the French States-General), ethnic or regional interests, or subunits of a federation. Where these factors are unimportant, in unitary states with limited regional autonomy, unicameralism often prevails. Sometimes, as in New Zealand and Denmark, this comes about through the abolition of one of the two chambers, or, as in Sweden, through the merger of the two chambers into a single one, while in others a second chamber has never existed.

Unicameral legislatures are also common in official Communist states such as the People's Republic of China and Cuba. Similarly, many formerly Communist states, such as Ukraine, Moldova and Serbia, have retained their unicameral legislatures, though others, such as Romania and Poland, adopted bicameral legislatures. Both the former Russian SFSR and the Union of Soviet Socialist Republics (USSR) were bicameral. The two chambers were the Soviet of Nationalities and the Soviet of the Union. The Russian Federation retained bicameralism after the dissolution of the USSR and the transition from existing socialism to capitalism.[1]

The principal advantage of a unicameral system is more efficient lawmaking, as the legislative process is much simpler and there is no possibility of deadlock. Proponents of unicameralism have also argued that it reduces costs, even if the number of legislators stay the same, since there are fewer institutions to maintain and support it.

The main weakness of a unicameral system can be seen as the lack of restraint on the majority, particularly noticeable in parliamentary systems where the leaders of the parliamentary majority also dominate the executive. There is also the risk that important sectors of society may not be adequately represented.

List of unicameral legislatures

Unibicameral Map
  Nations with a bicameral legislature.
  Nations with a unicameral legislature.
  Nations with a unicameral legislature and an advisory body.
  Nations with no legislature.

Approximately half of the world's sovereign states are currently unicameral, including both the most populous (the People's Republic of China) and the least populous (the Vatican City).

Many subnational entities have unicameral legislatures. These include the state of Nebraska and territories of Guam and the Virgin Islands in the United States, the Chinese Special Administrative Regions of Hong Kong and Macau, the Australian state of Queensland as well as the Northern Territory and the Australian Capital Territory, a majority of the provinces of Argentina, all of the provinces and territories in Canada, all of the German Bundesländer, all of the Regions of Italy, all of the Spanish Autonomous Communities, both the Autonomous Regions of Portugal, most of the States and union territories of India and all of the States of Brazil. In the United Kingdom, the devolved Scottish Parliament, National Assembly for Wales, London Assembly, and Northern Ireland Assembly are also unicameral.





Devolved governments


List of historical unicameral legislatures



Unicameralism in the United States

Within U.S. states, Nebraska is currently the only state with a unicameral legislature; after a statewide vote, it changed from bicameral to unicameral in 1937.[2][3] A 2018 study found that efforts to adopt unicameralism in Ohio and Missouri failed due to rural opposition.[3] There was a fear in rural communities that unicameralism would diminish their influence in state government.[3]

Local government legislatures of counties, cities, or other political subdivisions within states are usually unicameral and have limited lawmaking powers compared to their state and federal counterparts.

In 1999, Governor Jesse Ventura proposed converting the Minnesota Legislature into a single unicameral chamber.[4] Although debated, the idea was never adopted.

In a non-binding referendum held on July 10, 2004, voters in the U.S. territory of Puerto Rico approved changing its Legislative Assembly to a unicameral body by 456,267 votes in favor (83.7%) versus 88,720 against (16.3%). If both the territory's House of Representatives and Senate had approved by a ​23 vote the specific amendments to the Puerto Rico Constitution that are required for the change to a unicameral legislature, another referendum would have been held in the territory to approve such amendments. If those constitutional changes had been approved, Puerto Rico could have switched to a unicameral legislature as early as 2015.

On June 9, 2009, the Maine House of Representatives voted to form a unicameral legislature, but the measure did not pass the Senate.[5]

Because of legislative gridlock in 2009, former Congressman Rick Lazio, a prospective candidate for governor, has proposed that New York adopt unicameralism.[6]

The United States as a whole was subject to a unicameral Congress during the years 1781–1788, when the Articles of Confederation were in effect.

Unicameralism in the Philippines

Though the current Congress of the Philippines is bicameral, the country experienced unicameralism in 1898 and 1899 during the First Philippine Republic, from 1935 to 1941 during the Commonwealth Era and from 1943 to 1944 during the Japanese occupation. Under the 1973 Constitution, the legislative body was called Batasang Pambansa, which functioned also a unicameral legislature within a semi-presidential system form of government until 1986.

The ongoing process of amending or revising the current Constitution and form of government is popularly known as Charter Change. A shift to a unicameral parliament was included in the proposals of the constitutional commission created by former President Gloria Macapagal-Arroyo.[7] Unlike in the United States, senators in the Senate of the Philippines are elected not per district and state but nationally; the Philippines is a unitary state.[8] The Philippine government's decision-making process, relative to the United States, is more rigid, highly centralised, much slower and susceptible to political gridlock. As a result, the trend for unicameralism as well as other political system reforms are more contentious in the Philippines.[9]

While Congress is bicameral, all local legislatures are unicameral: the ARMM Regional Legislative Assembly, the Sangguniang Panlalawigan (Provincial Boards), Sangguniang Panlungsod (City Councils), Sangguniang Bayan (Municipal Councils), Sangguniang Barangay (Barangay Councils) and the Sangguniang Kabataan (Youth Councils).


  1. ^ Supreme Soviet of the Soviet Union, Wikipedia and Supreme Soviet of Russia, Wikipedia
  2. ^ "History of the Nebraska Unicameral". nebraskalegislature.gov. Retrieved 2015-04-17.
  3. ^ a b c Myers, Adam S. (2018). "The Failed Diffusion of the Unicameral State Legislature, 1934–1944". Studies in American Political Development. 32 (2): 217–235. doi:10.1017/S0898588X18000135. ISSN 0898-588X.
  4. ^ "One People – One House". News.minnesota.publicradio.org. 1999-04-29. Retrieved 2013-11-26.
  5. ^ "RESOLUTION, Proposing an Amendment to the Constitution of Maine To Establish a Unicameral Legislature" (PDF). Retrieved 2013-11-26.
  6. ^ One for All, Rick Lazio, New York Times, July 14, 2009
  7. ^ "Constitutional Commission proposals". Concom.ph. Retrieved 2013-11-26.
  8. ^ Softrigger Interactive (2008-02-25). "Philippines : Gov.Ph : About the Philippines". Web.archive.org. Archived from the original on February 25, 2008. Retrieved 2013-11-26.
  9. ^ "citation was not true it needs more references?". Concom.ph. Retrieved 2013-11-26.
1905 in Russia

Events from the year 1905 in Russia

2005 Puerto Rican unicameralism referendum

A referendum on how many chambers the Legislative Assembly should have was held in Puerto Rico on July 10, 2005. The proposed change to a unicameral legislature was supported by 83.94% of those voting, although voter turnout was just 22.58%. However, another referendum would have to be held to approve the specific amendments to the constitution that are required for the change. The House of Representatives subsequently let the bill die, so the changes were not realised. Had the changes been approved, the legislature would have become unicameral from 2009 onwards.

4th General Assembly of Newfoundland

The members of the 4th General Assembly of Newfoundland were elected in the Newfoundland general election held in 1848. The general assembly sat from December 14, 1848, to 1852.

With the passing of the Newfoundland Act of 1847 by the British Parliament,the members of the Legislative Council once again sat separately from the assembly, ending the experiment with unicameralism started in 1842. The first session of the assembly was held in a building owned by a member of the legislature. For the second session which started in 1850, the assembly met in the newly constructed Colonial Building.John Kent was chosen as speaker.Sir John Le Marchant served as civil governor of Newfoundland.


A bicameral legislature divides the legislators into two separate assemblies, chambers, or houses. Bicameralism is distinguished from unicameralism, in which all members deliberate and vote as a single group, and from some legislatures that have three or more separate assemblies, chambers, or houses. As of 2015, fewer than half the world's national legislatures are bicameral.Often, the members of the two chambers are elected or selected by different methods, which vary from country to country. This can often lead to the two chambers having very different compositions of members.

Enactment of primary legislation often requires a concurrent majority – the approval of a majority of members in each of the chambers of the legislature. When this is the case, the legislature may be called an example of perfect bicameralism. However, in many Westminster system parliaments, the house to which the executive is responsible can overrule the other house and may be regarded as an example of imperfect bicameralism. Some legislatures lie in between these two positions, with one house only able to overrule the other under certain circumstances.

Centralized government

A centralized government (also centralised government) is one in which power or legal authority is exerted or coordinated by a de facto political executive to which federal states, local authorities, and smaller units are considered subject. In a national context, centralization occurs in the transfer of power to a typically sovereign nation state. Menes, an ancient Egyptian pharaoh of the early dynastic period, is credited by classical tradition with having united Upper and Lower Egypt, and as the founder of the first dynasty (Dynasty I), became the first ruler to institute a centralized government.All constituted governments are, to some degree, necessarily centralized, in the sense that a theoretically federal state exerts an authority or prerogative beyond that of its constituent parts. To the extent that a base unit of society — usually conceived as an individual citizen — vests authority in a larger unit, such as the state or the local community, authority is centralized. The extent to which this ought to occur, and the ways in which centralized government evolves, forms part of social contract theory.


Landstinget was the upper house of the Rigsdag (the parliament of Denmark), from 1849 until 1953, when the bicameral system was abolished in favor of unicameralism. Landstinget had powers equal to the Folketing, which made the two houses of parliament hard to distinguish.

Originally, membership and the electorate was restricted, and the members were largely conservatives. Membership of the house was then restricted to certain sectors of society: only males with a certain net worth could hold a seat. In 1915, these restrictions were removed, and a few new members were appointed by the existing members.

Legislative Assembly of Puerto Rico

The Legislative Assembly of Puerto Rico (Spanish: Asamblea Legislativa de Puerto Rico) is the territorial legislature of the Commonwealth of Puerto Rico, responsible for the legislative branch of the government of Puerto Rico. The Assembly is a bicameral legislature consisting of an upper house, the Senate (Spanish: Senado) normally composed by 27 senators, and the lower house, the House of Representatives (Spanish: Cámara de Representantes) normally composed by 51 representatives. Eleven members of each house are elected at-large rather than from a specific legislative district with all members being elected for a four-year term without term limits.

The structure and responsibilities of the Legislative Assembly are defined in Article III of the Constitution of Puerto Rico which vests all legislative power in the Legislative Assembly. Every bill must be passed by both houses and signed by the Governor of Puerto Rico to become law. Each house has its unique powers. The constitution also states that each house shall be the unique judge on the legal capacity of its members. The constitution also grants parliamentary immunity to all elected members of the Legislative Assembly.

The assembly currently in session is the 18th Legislative Assembly of Puerto Rico, composed by the 26th Senate and the 30th House of Representatives—with each house composed by a two-thirds majority of members from the New Progressive Party (PNP).

The Legislative Assembly convenes at the Capitol in San Juan.

Legislative chamber

A legislative chamber or house is a deliberative assembly within a legislature which generally meets and votes separately from the legislature's other chambers. Legislatures are usually unicameral, consisting of only one chamber, or bicameral, consisting of two, but there are rare examples of tricameral and tetracameral legislatures.


A legislator (or lawmaker) is a person who writes and passes laws, especially someone who is a member of a legislature. Legislators are usually politicians and are often elected by the people of the state. Legislatures may be supra-national (for example, the European Parliament), national (for example, the United States Congress), regional (for example, the National Assembly for Wales), or local (for example, local authorities).

List of elections in 2005

The following elections occurred in the year 2005.

Elections in 2005

Electoral calendar 2005

Azerbaijani parliamentary election, 2005

Greenlandic parliamentary election, 2005

Maldivian parliamentary election, 2005

New Zealand general election, 2005

Organization of American States Secretary General election, 2005

United Nations Security Council election, 2005

Uzbekistani parliamentary election, 2004–2005

List of female speakers of national and territorial unicameral parliaments

In government, unicameralism (Latin uni, one + camera, chamber) is the practice of having one legislative or parliamentary chamber. Thus, a unicameral parliament or unicameral legislature is a legislature which consists of one chamber or house. Unicameral legislatures typically exist in small and homogeneous unitary states, where a second chamber is considered unnecessary.

Many women have been elected to parliaments around the world, starting around the first quarter of 20th century. Some of them were entrusted to take the position of Speaker of the parliament. This is a list of women who were chosen to serve as unicameral parliament speakers at the national and territorial level.

Lower house

A lower house is one of two chambers of a bicameral legislature, the other chamber being the upper house.Despite its official position "below" the upper house, in many legislatures worldwide, the lower house has come to wield more power. The lower house typically is the larger of the two chambers, i.e. its members are more numerous. A legislature composed of only one house is described as unicameral.

Member of Congress

A Member of Congress (MOC) is a person who has been appointed or elected and inducted into an official body called a congress, typically to represent a particular constituency in a legislature. Member of Parliament (MP) is an equivalent term in other jurisdictions.


In contrast to unicameralism, multicameralism is the condition in which a legislature is divided into several deliberative assemblies, which are commonly called "chambers" or "houses". This can include bicameralism with two chambers, tricameralism with three, tetracameralism with four branches, or a system with any amount more. The word "multicameral" can also relate in other ways to its literal meaning of "many chambered" with use in science or biology.

Many modern parliaments and congresses adopt a multicameral (usually bicameral) structure to provide multiple perspectives and a form of separation of powers within the legislature.

Party-list proportional representation

Party-list proportional representation systems are a family of voting systems emphasizing proportional representation (PR) in elections in which multiple candidates are elected (e.g., elections to parliament) through allocations to an electoral list. They can also be used as part of mixed additional member systems.In these systems, parties make lists of candidates to be elected, and seats get distributed to each party in proportion to the number of votes the party receives. Voters may vote directly for the party, as in Albania, Argentina, Turkey, and Israel; or for candidates whose vote total will pool to the party, as in Finland, Brazil and the Netherlands; or for a list of candidates, as in Hong Kong.

Voters in Luxembourg's multi-seat constituencies can choose between voting for a complete list of candidates of a single party ("list vote") or voting for individual candidates from one or several lists ("panachage").

The order in which a party's list candidates get elected may be pre-determined by some method internal to the party or the candidates (a closed list system) or it may be determined by the voters at large (an open list system) or by districts (a local list system).

Many variations on seat allocation within party-list proportional representation exist. The two most common are:

The highest average method, including the D'Hondt method (or Jefferson's method) used in Albania, Argentina, Austria, Bulgaria, Croatia, Cambodia, Estonia, Finland, Israel, Poland, Spain and many other countries; and the Sainte-Laguë method (or Webster's method) used in Norway, Sweden, New Zealand, the German Bundestag, and in six German states (e.g., North Rhine-Westphalia and Bremen).

The largest remainder (LR) methods, including the Hamilton method.List proportional representation may also be combined in various hybrids, e.g., using the additional member system.

List of main apportionment methods:

Macanese "d'Hondt method" (greatly favors small parties)

Webster/Sainte-Laguë method, LR-Hare (slightly favors very small parties when unmodified, if there is no election threshold)

LR-Droop (very slightly favors larger parties)

D'Hondt method (slightly favors larger parties)

Huntington-Hill method (greatly favors larger parties)

LR-Imperiali (greatly favors larger parties)While the allocation formula is important, equally important is the district magnitude (number of seats in a constituency). The higher the district magnitude, the more proportional an electoral system becomes - the most proportional being when there is no division into constituencies at all and the entire country is treated as a single constituency. More, in some countries the electoral system works on two levels: at-large for parties, and in constituencies for candidates, with local party-lists seen as fractions of general, national lists. In this case, magnitude of local constituencies is irrelevant, seat apportionment being calculated at national level.

In France, party lists in proportional elections must include as many candidates (and twice as many substitutes for the departmental elections) as there are seats to be allocated, whereas in other countries "incomplete" lists are allowed.


The Storting (Norwegian: Stortinget [²stuːʈɪŋə], "the great thing" or "the great assembly") is the supreme legislature of Norway, established in 1814 by the Constitution of Norway. It is located in Oslo. The unicameral parliament has 169 members, and is elected every four years based on party-list proportional representation in nineteen plurinominal constituencies. A member of the Storting is known in Norwegian as a stortingsrepresentant, literally "Storting representative".The assembly is led by a president and, since 2009, five vice presidents: the presidium. The members are allocated to twelve standing committees, as well as four procedural committees. Three ombudsmen are directly subordinate to parliament: the Parliamentary Intelligence Oversight Committee and the Office of the Auditor General.

Parliamentarianism was established in 1884. In 2009, qualified unicameralism was replaced by unicameralism, through the dissolution of the two chambers: the Lagting and the Odelsting.

Following the 2017 election, nine parties are represented in parliament: the Labour Party (49 representatives), the Conservative Party (45), the Progress Party (27), the Centre Party (19), the Christian Democratic Party (8), the Liberal Party (8), the Socialist Left Party (11), the Green Party (1), and the Red Party (1). Since 2018, Tone Wilhelmsen Trøen has been President of the Storting.


Tetracameralism (Greek: tetra-, four + Latin: camera, chamber) is the practice of having four legislative or parliamentary chambers. It is contrasted to unicameralism and bicameralism, which are far more common, and tricameralism, which is rarely used in government. No state currently has a tetracameral system.

Medieval Scandinavian deliberative assemblies were traditionally tetracameral, with four estates; the nobility, the clergy, the burghers and the peasants. The Swedish and Finnish Riksdag of the Estates maintained this tradition the longest, having four separate legislative bodies. Finland, as a part of Imperial Russia used the tetracameral Diet of Finland until 1906, when it was replaced by the unicameral Parliament.


Tricameralism is the practice of having three legislative or parliamentary chambers. It is contrasted with unicameralism and bicameralism, both of which are far more common.

The term was used in South Africa to describe the Parliament established under the apartheid regime's new South African Constitution of 1983. Other instances of tricameral legislatures in history include Simón Bolívar's model state. The word could also describe the French Estates-General, which had three 'estates', as well as the three chambers which comprised the Consular and Napoleonic (1799–1815) legislatures.

Unitary state

A unitary state is a state governed as a single power in which the central government is ultimately supreme. The central government may create (or abolish) administrative divisions (sub-national units). Such units exercise only the powers that the central government chooses to delegate. Although political power may be delegated through devolution to local governments by statute, the central government may abrogate the acts of devolved governments or curtail (or expand) their powers. A large majority of the world's states (165 of the 193 UN member states) have a unitary system of government.Unitary states stand in contrast with federations, also known as federal states. In federations, the sub-national governments share powers with the central government as equal actors through a written constitution, to which the consent of both is required to make amendments. This means that the sub-national units have a right of existence and powers that cannot be unilaterally changed by the central government.The United Kingdom of Great Britain and Northern Ireland is an example of a unitary state. Scotland, Wales and Northern Ireland have a degree of autonomous devolved power, but such power is delegated by the Parliament of the United Kingdom, which may enact laws unilaterally altering or abolishing devolution (England does not have any devolved power). Similarly in the Kingdom of Spain, where the devolved powers are delegated through the central government. Many unitary states have no areas possessing a degree of autonomy. In such countries, sub-national regions cannot decide their own laws. Examples are Romania, the Republic of Ireland and the Kingdom of Norway.

National unicameral legislatures
Dependent and
other territories
Non-UN states

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