Macintosh, AndrewCunliffe, Jancis2015-12-070813-300Xhttp://hdl.handle.net/1885/26887Over the past 30 years, increasing environmental and natural resource regulation has sparked debate about the protection of private property interests and provision of compensation to those affected by regulatory measures. Where these disputes involve the Commonwealth, it is not uncommon for property owners to reach for s 51(xxxi) of the Australian Constitution to bolster their claims for assistance. In the 2009 decision of ICM Agriculture Pty Ltd v Commonwealth (2009) 240 CLR 140; 170 LGERA 373, the High Court took an important step in clarifying the scope of s 51(xxxi). The decision provides a strong precedent in support of the notion that, for a law to give rise to an acquisition, it must either result in the Commonwealth (or a third party) obtaining an entitlement to possession and control of the plaintiff's property, or effectively sterilise the plaintiff's interest while providing a correlative proprietary benefit to another party. This article reviews the evolution of the High Court's approach to the "constitutional guarantee" and analyses ICM's place in s 51(xxxi) jurisprudence.Keywords: Commonwealth of Nations; compensation system; environmental management; legislation; private land; regulatory frameworkThe significance of ICM in the evolution of s 51 (xxxi)20122016-02-24