Prime Minister of New Zealand signed a number of international treaties. In 1967, Keith Holyoake became the first New Zealand prime minister to select candidates for the position of governor-general without any involvement of the British government. Holyoake advised the monarch, Queen Elizabeth II, to appoint Sir Arthur Porritt, the first New Zealand–born governor-general. After the mixed-member proportional (MMP) system was introduced in 1996, prime ministers have had to manage minority governments. The skill of MMP management was exemplified by Helen Clark's nine years as prime minister (1999–2008), when her Labour Party remained in power thanks to a range of confidence and supply agreements with
Prime Minister of the United Kingdom and other important honours. The British system of government is based on an uncodified constitution, meaning that it is not set out in any single document. The British constitution consists of many documents and most importantly for the evolution of the Office of the Prime Minister, it is based on customs known as constitutional conventions that became accepted practice. In 1928, Prime Minister H. H. Asquith described this characteristic of the British constitution in his memoirs:In this country we live ... under an unwritten Constitution. It is true that we have on the Statute-book great instruments like Magna Carta, the