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
Helen Clark ahead of Clark in preferred prime minister polls by eight points in the Fairfax Media Nielsen poll and four points in the One News Colmar Brunton poll. In the 2008 election campaign, Clark attacked the National Party as "insincere" in its promise to maintain many of her government's flagship projects, such as KiwiSaver and Kiwibank. National overtook Labour as the largest party following the 2008 election; Clark conceded defeat to Key and announced that she was standing down as party leader. On 11 November 2008 Clark was succeeded by Phil Goff as Leader of the Labour Party. In the first