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.
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
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 states, 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.
- National Assembly of Angola
- National Assembly of Armenia
- National Assembly of Azerbaijan
- Jatiyo Sangshad of Bangladesh
- National Assembly of Benin
- National Assembly of Botswana
- Legislative Council of Brunei
- National Assembly of Bulgaria
- National Assembly of Burkina Faso
- National Assembly of Cape Verde
- National Assembly of the Central African Republic
- National Assembly of Chad
- National People's Congress of the People's Republic of China
- Assembly of the Union of the Comoros
- Parliament of the Cook Islands
- Legislative Assembly of Costa Rica
- Sabor of Croatia
- National Assembly of People's Power of Cuba
- Folketing of Denmark
- House of Assembly of Dominica
- National Assembly of Djibouti
- National Parliament of East Timor
- National Assembly of Ecuador
- House of Representatives of Egypt
- Legislative Assembly of El Salvador
- National Assembly of Eritrea
- Riigikogu of Estonia
- Parliament of Fiji
- Parliament of Finland
- National Assembly of the Gambia
- Parliament of Georgia
- Parliament of Ghana
- Parliament of Greece
- Congress of Guatemala
- National Assembly of Guinea
- National People's Assembly of Guinea-Bissau
- National Assembly of Guyana
- National Congress of Honduras
- National Assembly of Hungary
- Althing of Iceland
- Islamic Consultative Assembly of Iran
- Council of Representatives of Iraq (provision exists for the founding of a "Council of Union", but no move to this effect has been initiated by the existing Council)
- Knesset of Israel
- House of Assembly of Kiribati
- Assembly of Kosovo
- Supreme Council of Kyrgyzstan
- National Assembly of Kuwait
- National Assembly of Laos
- Saeima of Latvia
- Parliament of Lebanon
- House of Representatives of Libya
- Landtag of Liechtenstein
- Seimas of Lithuania
- Chamber of Deputies of Luxembourg
- National Assembly of Malawi
- Majlis of the Maldives
- National Assembly of Mali
- Parliament of Malta
- Legislature of the Marshall Islands
- Parliament of Mauritania
- National Assembly of Mauritius
- Congress of Micronesia
- Parliament of Moldova
- National Council of Monaco
- State Great Khural of Mongolia
- Parliament of Montenegro
- Assembly of the Republic of Mozambique
- Parliament of Nauru
- Parliament of New Zealand
- National Assembly of Nicaragua
- National Assembly of Niger
- Assembly of Niue
- Supreme People's Assembly of North Korea
- Assembly of North Macedonia
- Storting of Norway
- National Assembly of Panama
- National Parliament of Papua New Guinea
- Congress of the Republic of Peru
- Assembly of the Republic of Portugal
- National Assembly of Saint Kitts and Nevis
- Legislative Assembly of Samoa
- National Assembly of São Tomé and Príncipe
- National Assembly of Senegal
- National Assembly of Serbia
- National Assembly of Seychelles
- Parliament of Sierra Leone
- Parliament of Singapore
- National Council of Slovakia
- National Assembly of South Korea
- Parliament of Sri Lanka
- National Assembly of Suriname
- Riksdag of Sweden
- Parliament of Syria
- Legislative Yuan of the Republic of China (Taiwan)
- National Assembly of Tanzania
- National Assembly of Togo
- Legislative Assembly of Tonga
- National Assembly of Tunisia
- Grand National Assembly of Turkey
- Assembly of Turkmenistan
- Parliament of Tuvalu
- Parliament of Uganda
- Verkhovna Rada of Ukraine
- Pontifical Commission for Vatican City State
- National Assembly of Venezuela
- National Assembly of Vietnam
- Assembly of Representatives of Yemen
- National Assembly of Zambia
- House of Assembly of the British Virgin Islands
- Legislative Assembly of the Cayman Islands
- Parliament of Greenland
- The Løgting of the Faroe Islands
- Parliament of Gibraltar
- Legislature of Guam
- Legislative Council of Hong Kong
- Legislative Assembly of Macau
- Legislative Assembly of the Falkland Islands
- Legislature of the U.S. Virgin Islands
- All legislatures and legislative councils of the regions and communities of Belgium
- All legislative assemblies of the provinces and territories of Canada
- All Landtage of the states of Germany
- All legislative assemblies of the states of Malaysia
- The legislature of the state of Nebraska, and council of the District of Columbia in the United States
- Parliament of Queensland and the legislative assemblies of the territories of Australia (but not the other states)
- Provincial legislatures of the provinces of South Africa
- Narodna skupština of Republika Srpska
- All legislative assemblies in all states of Brazil
- All legislatures in all states of Mexico
- 15 of the provinces of Argentina – Chaco, Chubut, Córdoba, Formosa, Jujuy, La Pampa, La Rioja (Argentina), Misiones, Neuquén, Río Negro (Argentina), San Juan, Santa Cruz, Santiago del Estero, Tierra del Fuego, Tucumán and the autonomous city of Buenos Aires.
- 22 of the states of India – Arunachal Pradesh, Assam, Chhattisgarh, Goa, Gujarat, Haryana, Himachal Pradesh, Jharkhand, Kerala, Madhya Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, Odisha, Punjab, Rajasthan, Sikkim, Tamil Nadu, Tripura, Uttarakhand and West Bengal; and 2 of the union territories – Delhi and Puducherry
- All legislatures of the provinces in Pakistan – Azad Kashmir, Balochistan, Gilgit Baltistan Khyber Pakhtunkhwa, Punjab and Sindh
- Iraqi Kurdistan Parliament
- Northern Ireland Assembly
- [[INLINE_IMAGE|//upload.wikimedia.org/wikipedia/commons/thumb/1/10/Flag_of_Scotland.svg/23px-Flag_of_Scotland.svg.png|//upload.wikimedia.org/wikipedia/commons/thumb/1/10/Flag_of_Scotland.svg/35px-Flag_of_Scotland.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/10/Flag_of_Scotland.svg/46px-Flag_of_Scotland.svg.png 2x|Scotland|h14|w23|thumbborder flagicon-img flagicon-img]] Scottish Parliament
- National Assembly for Wales
- Parliaments of the autonomous communities of Spain
- All regional councils of France
- Local People's Congresses of all levels of provinces, regions and municipalities of the People's Republic of China
List of historical unicameral legislatures
- The First Protectorate Parliament and Second Protectorate Parliament of the Kingdom of England, regulated by the Instrument of Government (dissolved)
- Parliament of the Kingdom of Scotland until 1707 (dissolved)
- Congress of the Confederation was unicameral before being replaced in 1789 by the current, bicameral United States Congress.
- Congress of Deputies of Second Spanish Republic was unicameral between 1931 and 1936. Dissolved at the end of Spanish Civil War; the present Spanish Parliament (established in 1978) is bicameral.
- Supreme Assembly of Uzbekistan was unicameral before being replaced in 2005 by the current, bicameral Supreme Assembly.
- National Assembly of Cameroon was unicameral before being replaced in 2013 by the current, bicameral Parliament of Cameroon.
- Chamber of People's Representative of Equatorial Guinea was unicameral before being replaced in 2013 by the current, bicameral Parliament of Equatorial Guinea.
- National Assembly of Kenya was the country's unicameral legislature before becoming the lower house of the bicameral Parliament of Kenya in 2013.
- National Assembly of Ivory Coast was the country's unicameral legislature before becoming the lower house of the bicameral Parliament of Ivory Coast in 2016.
- General Assembly of Georgia until 1789
- General Assembly of Pennsylvania until 1790
- General Assembly of Vermont until 1836
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. A 2018 study found that efforts to adopt unicameralism in Ohio and Missouri failed due to rural opposition. There was a fear in rural communities that unicameralism would diminish their influence in state government.
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.
The U.S. territory of Puerto Rico held a non-binding referendum in 2005. Voters 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 2⁄3 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.
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 ( 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. 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. 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.
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).