At self-government, on 1 December 1973, Australia transferred to a democratically-elected government all powers except those concerning foreign affairs, defense and the legal system. These remaining powers were handed over when PNG became completely independent on 15 September 1975. The Australian Prime Minister, Gough Whitlam, who strongly supported Independence, and PNG’s Chief Minister Michael Somare had agreed on this staged transfer of powers. Not all PNGans supported self-goverment and Independence. Some highlanders were afraid that, when Australia left, the country would be dominated by the better educated lowland and island elite. The transition was speeded by the election, in Australia, of a Labor Government whose leader, Gough Whitlam, was committed to early self-government.
In the period between self-government and Independence the House of Assembly debated reports of its Constitutional Planning Committee on matters such as the form of government PNG should adopt; eligibility for citizenship; a parliamentary standing committees system; provincial government; and the control of foreign investment. Most of these matters were resolved in the Constitution which was adopted, after extensive debate, on 15 August 1975. The question of provincial government was postponed until after Independence. On Independence Day, 16 September 1975, the Governor-General, Sir John Guise, swore allegiance to Her Majesty Queen Elizabeth II, and declared loyalty to the Independent State of Papua New Guinea. The Prime Minister, Michael Somare, government ministers, and judges of the National and Supreme Courts declared loyalty to the Independent State of Papua New Guinea and its people and the Constitution and laws of PNG.