“Peace, order and good government” requirements such as section 2 of the Australia Act 1986 (Cth) impose substantive limitations on the powers of State legislatures.

 State Parliament’s possess plenary power which could enable them to pass unfair or discriminatory laws unless otherwise constrained by the Commonwealth Constitution.

State parliaments possess residual plenary power, and do not need to identify or rely on a specific head of power when legislating on any subject matter.

“Peace, order and good government” requirements such as section 2 of the Australia Act 1986 (Cth) in respect of States are plenary and do not impose substantive limitations on the powers of State legislatures.