New Zealand House of Representatives in the context of "Members of parliament"

The New Zealand Parliament (Māori: Pāremata Aotearoa) is the unicameral legislature of New Zealand, consisting of the monarch (represented by the governor-general) and the New Zealand House of Representatives. It was established in 1854 and is one of the oldest continuously functioning legislatures in the world. It was bicameral until the abolition of the New Zealand Legislative Council at the end of 1950. Parliament's seat, the capital of New Zealand, has been Wellington since 1865. It has met in its current building, Parliament House, since 1922.

The House of Representatives normally consists of 120 members of Parliament (MPs), though sometimes more due to overhang seats. There are 72 MPs elected directly in electorates while the remainder of seats are assigned to list MPs based on each party's share of the total party vote. Māori were represented in Parliament from 1867, and in 1893 women gained the vote. Although elections can be called early, every three years Parliament is dissolved and goes up for reelection.

The constitution of New Zealand is the sum of laws and principles that determine the political governance of New Zealand. Unlike many other nations, New Zealand has no single constitutional document. It is an uncodified constitution, sometimes referred to as an "unwritten constitution", although the New Zealand constitution is in fact an amalgamation of written and unwritten sources. The Constitution Act 1986 has a central role, alongside a collection of other statutes, orders in Council, letters patent, decisions of the courts, principles of the Treaty of Waitangi, and unwritten traditions and conventions. There is no technical difference between ordinary statutes and law considered "constitutional law"; no law is accorded higher status. In most cases the New Zealand Parliament can perform "constitutional reform" simply by passing acts of Parliament, and thus has the power to change or abolish elements of the constitution. There are some exceptions to this though – the Electoral Act 1993 requires certain provisions can only be amended following a referendum.

After decades of self-governance, New Zealand gained full statutory independence from Britain in 1947. It is a constitutional monarchy with a parliamentary democracy. The monarch of New Zealand is the head of state – represented in the Realm of New Zealand by the governor-general – and is the source of executive, judicial and legislative power, although effective power is in the hands of ministers drawn from the democratically elected New Zealand House of Representatives. This system is based on the "Westminster model", although that term is increasingly inapt given constitutional developments particular to New Zealand. For instance, New Zealand introduced a unicameral system within a decade of its statutory independence.

The New Zealand Government (Māori: Te Kāwanatanga o Aotearoa) is the central government through which political authority is exercised in New Zealand. As in most other parliamentary democracies, the term "Government" refers chiefly to the executive branch, and more specifically to the collective ministry directing the executive. Based on the principle of responsible government, it operates within the framework that "the [King] reigns, but the government rules, so long as it has the support of the House of Representatives". The Cabinet Manual describes the main laws, rules and conventions affecting the conduct and operation of the Government.

Executive power is exercised by ministers, all of whom are sworn into the Executive Council and accountable to the elected legislature, the House of Representatives. Several senior ministers (usually 20) constitute a collective decision-making body known as the Cabinet, which is led by the prime minister (currently Christopher Luxon). A few more ministers (usually junior or supporting) are part of the Executive Council but are outside Cabinet. Most ministers have a portfolio of specific responsibilities such as departments or policy areas, although ministers without portfolio can be appointed.

The New Zealand Legislative Council was the upper house of the General Assembly of New Zealand from 1853 to 1950. An earlier legislative council existed from 1841 when New Zealand became a colony; it was reconstituted as the upper house of a bicameral legislature when New Zealand became self-governing in 1852, which came into effect in the following year.

Unlike the elected lower house, the House of Representatives, the Legislative Council was wholly appointed by the governor-general. The New Zealand Constitution Act 1852 had authorised the appointment of a minimum of ten councillors. Beginning in the 1890s, the membership of the upper house became controlled by government of the day. As a result, the Legislative Council possessed little influence. While intended as a revising chamber, in practice, debates and votes typically simply replicated those in the lower house. It was abolished by an Act of Parliament in 1950, with its last sitting in December 1950.

New Zealand politics have featured a strong party system since the early 20th century. Usually, all members of Parliament's unicameral House of Representatives belong to a political party.

The centre-left New Zealand Labour Party and the centre-right New Zealand National Party are New Zealand's two major parties, having jointly contested each election since 1938; they are the only two New Zealand political parties to have won the popular vote in four consecutive elections twice. Labour won the popular vote from the 1938 election through to 1946 and again from 1978 through to 1987 – although during the latter period National twice disproportionately gained a majority of seats. Likewise, National won the popular vote from 1960 through to 1969, and then again from 2008 through to 2017, but in the final year could not form a coalition government under proportional representation.