[6][7] The New Zealand Parliament is specifically modelled on the Westminster system of parliamentary representation, developed in the United Kingdom of Great Britain and Ireland.

The Bill of Rights 1688 (which has been ratified as law in New Zealand)[9] established a system where parliaments would be regularly elected.

[11] The members of the House were elected under the first-past-the-post (FPP) voting system, while those of the Council were appointed by the governor.

[18] Under the Constitution Act, legislative power was also conferred on New Zealand's provinces (originally six in number), each of which had its own elected provincial council.

[12] New Zealand had representatives of the indigenous population in its parliament from an early date, in contrast to many other colonial states.

[20] One historical speciality of the New Zealand Parliament was the country quota, which gave greater representation to rural politics.

From 1889 on (and even earlier in more informal forms), districts were weighted according to their urban/rural split (with any locality of less than 2,000 people considered rural).

Those districts which had large rural proportions received a greater number of nominal votes than they actually contained voters – as an example, in 1927, Waipawa, a district without any urban population at all, received an additional 4,153 nominal votes to its actual 14,838 – having the maximum factor of 28% extra representation.

[26][28][29] On 10 February 2021, Mallard announced that ties were no longer compulsory in Parliament following a Standing Orders meeting where the majority voted in favour of Te Pāti Māori's submission calling for the elimination of neckties as part of Parliament's compulsory business attire.

[30] In 2024, the 2023 Standing Orders introduced two new "scrutiny weeks" to the Parliamentary calendar, which allows select committees to scrutinise government and public sector spending plans.

[31][32] Based on the Westminster system,[33] the New Zealand Parliament is supreme, with no other government institution able to override its decisions.

[34] For example, the New Zealand Bill of Rights Act 1990 is a normal piece of legislation, not superior law, as codified constitutions are in some other countries.

This results from the role of the monarch to sign into law (i.e. give the Royal Assent to) the bills that have been passed by the House of Representatives.

[44] Ministers in the New Zealand Government are drawn from amongst the members of the House of Representatives (with the possible exception of brief periods following an election).

[45] The government of the day, and by extension the prime minister, must achieve and maintain the support of the House in order to gain and remain in power.

[3] The Government is dependent on Parliament to implement its legislative agenda, and has always required the House's approval to spend money.

[49] With the passing of the New Zealand Constitution Act 1852, the Legislative Council was reconstituted as the upper house of the General Assembly.

[16] It was eventually decided that the Council was having no significant impact on New Zealand's legislative process; its final sitting was on 1 December 1950.

[50] In September 1950, the National government of Sidney Holland set up a constitutional reform committee to consider an alternative second chamber, chaired by Ronald Algie.

[51] The Senate would have the power to revise, initiate or delay legislation, to hear petitions, and to scrutinise regulations and Orders in Council, but the proposal was rejected by the Prime Minister and by the Labour opposition, which had refused to nominate members to the committee.

[54] However, following objections from the Labour opposition, which derided it as a red herring,[55] and other supporters of the mixed-member proportional (MMP) representation system,[56] the Senate question was removed by the Select Committee on Electoral Reform.

[53] In 2010, the New Zealand Policy Unit of the Centre for Independent Studies proposed a Senate in the context of the 2011 referendum on MMP.

The Constitution Act 1986 outlines that the governor-general is responsible for dissolving Parliament,[note 1][23] which is done by royal proclamation.

[59] Upon completion of the election, the governor-general, on the advice of the prime minister, then issues a proclamation summoning Parliament to assemble.

[46] A new parliamentary session is marked by the Opening of Parliament, during which the governor-general reads the Speech from the Throne, on the King's behalf.

[3] If a bill passes its third reading, it is delivered to the governor-general by the clerk of the House of Representatives, who, assuming that constitutional convention is followed, will grant Royal Assent as a matter of course.

Some constitutional lawyers, such as Professor Philip Joseph, believe the governor-general does retain the power to refuse Royal Assent to bills in exceptional circumstances—specifically if democracy were to be abolished.