New Zealand's politics: one chamber held in check by proportional votes

What holds the constitution together

There is no single founding text. Wikipedia's account of the system lists the parts: certain Acts of the British and New Zealand Parliaments, the principles of the Treaty of Waitangi and constitutional conventions. The Constitution Act 1986, in force from 1 January 1987, gathers the core provisions into one statute. Its long title records that it ends the New Zealand Constitution Act 1852 of the British Parliament as part of New Zealand law, and section 15 states that no Act of the British Parliament passed after it extends to New Zealand.

The Act is ordinary law. So are the New Zealand Bill of Rights Act 1990 and the Human Rights Act 1993, which protect civil rights but are not entrenched and can be changed by a simple majority in the House. Law comes from three places: English common law, certain British statutes passed before 1947 such as the Bill of Rights 1689, and statutes of the New Zealand Parliament. The courts interpret the common law to keep it in line with the United Kingdom and similar jurisdictions.

The Act was drafted after the crisis of 1984, when an incoming government reviewed the constitutional structures, and it has been amended since: the online text carries amendments of 1987, 1999, 2005 and 2026.

Who holds the Crown's powers in law

Section 2 of the Constitution Act names "the Sovereign in right of New Zealand" as head of state and the Governor-General, appointed by the Sovereign, as the Sovereign's representative. The monarchy has been legally distinct from the British one since the Statute of Westminster Adoption Act 1947. Every power the Governor-General holds under an Act is a royal power that either may exercise. In practice the Governor-General appoints and dismisses ministers, dissolves Parliament and gives the royal assent that turns a bill into law, and acts on the advice of ministers.

That advice comes through the Executive Council, which the Governor-General chairs and which is made up of all ministers. Section 6 requires every minister to be a member of Parliament, with a short grace period for a defeated candidate. Most ministers sit in the Cabinet, which takes decisions collectively and answers for them collectively. The prime minister is, by convention, the parliamentary leader of the largest governing party and holds the office because a majority of the House supports the government; a successful motion of no confidence forces the government either to resign or to seek an early election.

Why Parliament has a single chamber

Section 14 defines Parliament as the Sovereign and the House of Representatives, the same body that was called the General Assembly under the 1852 Act. There was a second chamber, the Legislative Council, until 1951. It was the council that blocked women's suffrage in 1891 and 1892 before passing it by 20 votes to 18 in 1893. Since its abolition a bill becomes law once the House passes it and the Sovereign or the Governor-General signs it.

The term of Parliament is three years from the return of the writs, and section 17 adds the words "and no longer". An election may be called earlier. The vote is nearly universal for permanent residents aged 18 and over. Local councils, regional, city and district, are elected every three years as well, and have only the powers Parliament gives them under the Local Government Act 2002; police and education are run by central government. Local government has rested on statute from the start: the first Municipal Corporations Act was passed by the Legislative Council in 1842.

How proportional voting changed who governs

Almost every election between 1853 and 1996 was held under first past the post; the only exceptions were the second-ballot elections of 1908 and 1911. Two parties dominated from 1935: Labour, formed in 1916, and National, formed in 1936 from a merger of the conservative parties. Criticism of the system grew after Labour lost the elections of 1978 and 1981 while winning more votes overall than National. A non-binding referendum in 1992 led to a binding one at the 1993 election, and the first election under mixed-member proportional representation was held in 1996.

The Electoral Commission describes the system from the voter's side. Each voter has two votes: a party vote, which largely decides how many seats each party gets, and an electorate vote for a local candidate, who wins by taking the most votes. A party must win at least 5% of the party vote or one electorate seat to enter Parliament. Electorate winners take their seats first, and the rest are filled from ranked party lists, so that a party's share of seats is about the same as its share of the party vote. Some elections have produced an overhang, leaving the House with more than 120 members for the term.

The effect was immediate. At least five parties have been elected at every general election since 1996. In the first eight elections under the system, 1996 to 2017, no party won a majority of seats, and governments were formed as coalitions or as minority governments relying on confidence and supply agreements, in which a party agrees to back the government on votes of confidence and the budget. The 2020 election produced the first single-party majority under the system. After the 2023 election three parties formed a coalition government, the first of that size. Parliament has twice legislated against MPs leaving the party they were elected for, known locally as waka-jumping: a law of 2001 that expired in 2005, and the Electoral (Integrity) Amendment Act 2018. Parties must register with the Electoral Commission to contest the party vote, and the law caps foreign donations at NZ$50 and anonymous donations at NZ$1,500.

How the right to vote was widened

The New Zealand Constitution Act 1852 set the rules for the first elections, held in 1853. The vote went to male British subjects over 21 who owned property, but the property bar was set low: by the late 1850s, by the account in Wikipedia's history of the system, 75% of adult European men in the colony could vote, against 20% in England and 12% in Scotland. Around 100 Māori chiefs voted in 1853. From 1858 gold miners holding a one-pound licence could vote, and in 1870 there were 41,500 registered voters with a further 20,000 miners entitled.

Women voted for the first time at the general election later in 1893, with a turnout of 85% against 70% among men. They became eligible to stand in 1919, when three women did, and the first woman to win a seat was Elizabeth McCombs in 1933. Mabel Howard became the first woman in a New Zealand cabinet in 1947. From March 2005 to August 2006 the Sovereign, the Governor-General, the Prime Minister, the Speaker and the Chief Justice were all women. After the 2020 election women held half of the 120 seats in the House.

Where Māori representation fits the system

Four Māori electorates were created in 1867 under a bill introduced by Donald McLean, which gave the vote to all Māori men over 21, twelve years before European men had a universal franchise. There are seven Māori electorates now, elected from a separate Māori roll. Since 1967 Māori candidates have been able to stand in general electorates, and since 1975 every Māori voter has been able to choose between the Māori roll and the general roll.

The Treaty of Waitangi sits in the system through statute and through an inquiry body. The Ministry for Culture and Heritage notes that the Treaty is not part of domestic law except where an Act refers to its principles; by 2021 more than 35 principal Acts did. The Waitangi Tribunal, set up by the Treaty of Waitangi Act 1975, describes itself as a permanent commission of inquiry closer to the judicial end of the spectrum. It hears claimants and the Crown and reports whether a claim is well founded, with recommendations, and in most hearings the protocol of the marae is followed. Settlements are negotiated with the government, which has formally apologised to iwi affected by the wars and confiscations. The Māori Lands Act 2016 was printed in both te reo Māori and English.

What the principles should mean is a recurring political question. A bill to delete references to them failed at its second reading in November 2007, and the ACT party has proposed a referendum to redefine them. An RNZ-Reid Research poll in 2026 found 38% saying the Treaty had too much influence over government decisions, 34% about the right amount and 16% too little.

How the courts are arranged

The courts run in four levels: the District Court, which includes the Youth Court; the High Court, which takes serious criminal cases and civil matters and hears appeals; the Court of Appeal; and the Supreme Court. The Supreme Court was established under the Supreme Court Act 2003, began sitting in 2004 and replaced the Privy Council in London as the court of last resort.

The Chief Justice, who presides over the Supreme Court, is appointed by the Governor-General on the prime minister's advice. Other senior judges are appointed on the advice of the Chief Justice, the Attorney-General and the Solicitor-General, and a judge can be removed only by the Attorney-General on an address of the House for proved misbehaviour. Appointments are made on qualifications, personal qualities and experience, and fixed rules on tenure keep judges independent of the government of the day.

Who New Zealand stands with abroad

New Zealand was a founding member of the United Nations in 1945 and is a member of the Commonwealth and the OECD. In its own region it belongs to the Pacific Islands Forum and the Pacific Community, and further out to Asia-Pacific Economic Cooperation, the East Asia Summit and the ASEAN Regional Forum. Its free-trade agreements include Closer Economic Relations with Australia, dated to 1982 in one Wikipedia account and to 1983 in another, which reached total free trade between the two countries in 1990, and an agreement with China.

The defining break came in the 1980s. The ANZUS treaty of 1951 bound New Zealand to Australia and the United States, but the New Zealand Nuclear Free Zone, Disarmament, and Arms Control Act 1987 barred visits by nuclear-powered ships, and New Zealand was suspended from the alliance. Wikipedia's account notes that the anti-nuclear position has been government policy irrespective of party since the 1990s, and that working relations with the United States and Australia continued.

Responsibility in the Pacific is written into the realm. Britannica records that New Zealand administers Tokelau and claims a section of Antarctica, the Ross Dependency, and that the Cook Islands and Niue are self-governing states in free association with it. Much of New Zealand's foreign aid goes to Pacific island states, and many Pacific people migrate to New Zealand for work.