Parliamentary democracies in the context of Bicameral legislature

Parliamentary sovereignty, also called parliamentary supremacy or legislative supremacy, is a concept in the constitutional law of some parliamentary democracies. It holds that the legislative body has absolute sovereignty and is supreme over all other government institutions, including executive or judicial bodies. It also holds that the legislative body may change or repeal any previous legislation and so it is not bound by written law (in some cases, not even a constitution) or by precedent. Changes to the constitution typically require a supermajority, often two thirds of votes instead of one half.

In some countries, parliamentary sovereignty may be contrasted with separation of powers and constitutionalism, which limits the legislature's scope often to general law-making and makes it subject to external judicial review, where laws passed by the legislature may be declared invalid in certain circumstances.

A parliamentary leader is a political title or a descriptive term used in various countries to designate the person leading a parliamentary group or caucus in a legislative body, whether it be a national or sub-national legislature. They are their party's most senior member of parliament (MP) in most parliamentary democracies.

A party leader may be the same person as the parliamentary leader, or the roles may be separated.

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.