Prime Minister of New Zealand ministerial power; in 1912 Thomas Mackenzie was the last prime minister to lose power through an unsuccessful confidence motion in the House of Representatives. One change brought about by the First World War was direct participation in governing the British Empire. Previously, New Zealand prime ministers had attended occasional colonial and imperial conferences, but they otherwise communicated with London through the governor (a position then appointed by the British government). In 1917, however, British Prime Minister David Lloyd George offered the New Zealand prime minister a seat in the Imperial War Cabinet, the British Empire's wartime coordinating body. In 1919,
Acting prime minister Minister, served as Acting Prime Minister for six days, after Norman Kirk died in office in 1974. Deputy Prime Minister Winston Peters was serving as Acting Prime Minister as of 21 June 2018 until 2 August 2018, while Jacinda Ardern took maternity leave. Prior to the establishment of the Deputy Prime Minister role, a senior Minister would be appointed to act as Prime Minister when, for example, the incumbent was travelling overseas. In the current era, when both the Prime Minister and Deputy Prime Minister are unavailable, the next highest ranking minister who is available will be asked to act