Statute of Westminster adopted

New Zealand was styled a dominion rather than a colony in 1907, but few New Zealanders then wanted greater independence from the United Kingdom. NZHistory lists racial affinity, language, culture, defence and trade links as the ties that bound most of them to the wider 'Britannic world'. In 1926, after pressure from the Irish, South Africans and Canadians, the Balfour Declaration described Britain and the dominions as 'autonomous Communities within the British Empire, equal in status, in no way subordinate one to another'. Prime Minister Gordon Coates called it a 'poisonous document', and others deplored the 'damned Statute of Westminster propaganda'.

The British Parliament enacted the Statute of Westminster on 11 December 1931. Its preamble took in the Balfour formula, and its chief operative clause provided that no British Act would apply in a dominion unless that dominion had 'requested and consented to' it. The statute applied at once to Canada, South Africa and the Irish Free State. New Zealand did not want to be named in it, and agreed only on condition that the operative sections would not apply until its own Parliament adopted them; Australia and Newfoundland took the same option. In practice New Zealand acted as if the statute applied, especially after the first Labour government took office in 1935 (see The first Labour government). It took an independent line in the League of Nations and made its own decision to enter the Second World War in 1939 (see New Zealand declares war on Germany). In 1939 the historian J. C. Beaglehole urged that New Zealand 'should adopt the Statute of Westminster as soon as possible'.

Peter Fraser, prime minister from 1940, told Parliament in 1944 that he was aware of 'the paradox that, the freer we become, the closer we draw together'. That year Labour proposed adopting the statute in the Speech from the Throne, but the National opposition attacked the idea as disloyal to Britain. National's Tauranga MP, Frederick Doidge, whose loyalty to the Crown Te Ara's biography of him describes as 'almost a religion', was among the critics, and the proposal was set aside for the rest of that parliamentary term. In August 1947 the National leader, Sidney Holland, introduced a bill to abolish the Legislative Council, Parliament's appointed upper house. It was defeated, partly on the grounds that New Zealand lacked the autonomy from the United Kingdom to take this action. In Te Ara's account, Fraser realised that 'constitutional technicalities had eventually to accord with political realities'. The adoption bill passed its third reading on 21 November 1947 and received the royal assent on 25 November.

The Statute of Westminster Adoption Act 1947 adopted sections two to six of the British statute. It provided that New Zealand's request and consent to any British Act would be 'made and given by the Parliament of New Zealand, and not otherwise'. In the same year New Zealand gained full power to amend the New Zealand Constitution Act 1852, which cleared the way for abolishing the upper house. National won the 1949 election on a platform that included abolition, and the Legislative Council sat for the last time on 1 December 1950; the abolition Act came into effect on 1 January 1951. New Zealand citizenship followed under the British Nationality and New Zealand Citizenship Act 1948, although holders of New Zealand citizenship remained 'British subjects'.

The Constitution Act 1986 repealed the Statute of Westminster, the 1947 amendment act and the New Zealand Constitution Act 1852. NZHistory says it removed the last faint provision for the British Parliament to make laws for New Zealand, and Te Ara dates full legal independence from that Act. The Supreme Court Act 2003 later replaced Britain's Privy Council with a New Zealand Supreme Court as the country's final court of appeal. Attorney-General Margaret Wilson said the change was meant 'to recognise that New Zealand is an independent nation with its own history and tradition'. Not everyone welcomed it: some Māori saw the Privy Council as a more direct extension of Crown authority and a guarantor of the Treaty of Waitangi.