Constitutional conventions adopted in 1930 , following the Imperial Conference held that year , increased the domestic and international prestige of the prime minister . The Statute of Westminster 1931 confirmed that Dominions had exclusive power to make their laws . New Zealand initially resisted greater autonomy and did not adopt the statute until 1947 . Increasingly , however , New Zealand began to act independently in foreign affairs . During the 1940s the prime minister 's profile rose as 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
Imperial Conference
1930 Imperial Conference
Prime Minister of New Zealand