Newcrest Mining (WA) Ltd v the Commonwealth

In Newcrest Mining (WA) Ltd v The Commonwealth, the High Court of Australia considered the validity of proclamations made under the *National Parks and Wildlife Conservation Act 1975* (Cth) that affected mining leases in the Northern Territory. The dispute centred on whether these proclamations, which effectively prohibited mining activities, constituted an acquisition of property by the Commonwealth otherwise than on just terms, contrary to section 51(xxxi) of the Constitution. The court also had to determine the interplay between the Commonwealth's legislative power under section 122 of the Constitution (relating to territories) and the limitations imposed by section 51(xxxi).

The primary legal issues before the High Court were: (1) whether the proclamations made under section 7(8) of the *National Parks and Wildlife Conservation Act 1975* (Cth) effected an acquisition of property within the meaning of section 51(xxxi) of the Constitution; (2) whether section 51(xxxi) operated as a limitation on the legislative power of the Commonwealth under section 122 of the Constitution when a law could be characterised as having a dual character; and (3) the validity of certain mining leases and their renewals under Northern Territory legislation in light of the subsequent Commonwealth proclamations.

The Court reasoned that the proclamations, by prohibiting mining operations on the leased land, did constitute an acquisition of property for the purposes of section 51(xxxi). It held that section 51(xxxi) is a limitation on the legislative power of the Commonwealth, including when that power is exercised under section 122. The Court found that the power to make proclamations under section 7(8) of the *National Parks and Wildlife Conservation Act 1975* (Cth) was not exclusively referable to section 122, and therefore the requirement of just terms under section 51(xxxi) applied. The Court also considered the status of the mining leases, finding that some were still in force at the time of the relevant proclamations, while others had expired.

The High Court allowed the appeal, setting aside the orders of the Full Court of the Federal Court in part. It declared that certain mining leases were still in force immediately prior to the proclamations made on 13 November 1989 and 21 June 1991, respectively. Crucially, it declared that the proclamations made on 13 November 1989 and 21 June 1991 were invalid to the extent that they effected acquisitions of property from Newcrest Mining (WA) Limited other than on just terms, as required by section 51(xxxi) of the Constitution. The Commonwealth and the Director of National Parks and Wildlife were ordered to pay the costs of Newcrest Mining (WA) Limited.