What it does
The Papua New Guinea Independence Act 1975 (No. 98 of 1975) is a short, declarative statute whose sole purpose is to terminate Australia's legal and sovereign connection with the territory known as Papua New Guinea on the eve of 16 September 1975. Section 4 provides the central operative rule: "On the expiration of the day preceding Independence Day, Australia ceases to have any sovereignty, sovereign rights or rights of administration in respect of or appertaining to the whole or any part of Papua New Guinea." Independence Day is defined in s 3(1) as 16 September 1975.
Section 5 then executes the repeal mechanism. On the same date (the expiration of 15 September 1975) two things happen: (a) the Acts listed in Schedule 1 are repealed outright, and (b) every other Act, and every Imperial Act, that had extended to the whole or any part of Papua New Guinea as part of its law "ceases so to extend". The Schedule itself is a clean list of eighteen statutes ranging from the Papua and New Guinea Act 1949 through successive amending Acts up to the Papua New Guinea Act (No. 2) 1974 and the Papua New Guinea Act 1975. The effect is surgical: the entire statutory edifice that had governed the administrative union is dismantled at the stroke of midnight on 15 September 1975.
Section 6 confers a limited regulation-making power on the Governor-General. Regulations may deal with "matters arising out of or connected with the attainment of the independence of Papua New Guinea, including regulations making modifications or adaptations of any Act". However, any such regulations made before Independence Day cannot take effect before that day. This is a transitional tidy-up power rather than a substantive ongoing rule-making authority. Sections 1 and 2 are formal: the short title and the commencement on the day of Royal Assent (9 September 1975).