Strickland v Rocla Concrete Pipes Ltd, also known as the Concrete Pipes Case, is a High Court of Australia case that discusses the scope of the corporations power in section 51(xx) of the Australian Constitution. This was an important case in Australian constitutional law because it overruled the decision in the earlier case of Huddart, Parker & Co Pty Ltd v Moorehead, which held that the corporations power only extended as far as the regulation of their conduct in relation to their transactions with or affecting the public. Since this case, the Commonwealth has had at least the ability to regulate the trading activities of trading corporations, thus opening the way for an expansion in Commonwealth power. The width of this power was later considered again in the cases of Actors and Announcers Equity Association v Fontana Films, Commonwealth v Tasmania (the Tasmanian Dam Case), Re Dingjan; Ex parte Wagner, and New South Wales v Commonwealth (the WorkChoices Case). Background Section 43 of the Trade Practices Act 1965-1969 (Cth) made certain agreements between competitors restricting competition "examinable", and the respondents in this case were charged with breaching that section. The agreements in question were exclusively related to trade in Queensland. Because this is purely intrastate trade, the respondents would not have fallen within the legislative power granted by section 51(i) of the Constitution. The Commonwealth Industrial Court, at first instance, rejected the charge, following Huddart, Parker & Co Pty Ltd v Moorehead, in which it was held that a law with respect to the trading activities of constitutional corporations was not within power. Decision Corporations power The Court unanimously rejected the decision in Huddart, Parker & Co Pty Ltd v Moorehead, holding that it was based on the rejected doctrine of reserved State powers, which was abolished in Amalgamated Society of Engineers v Adelaide Steamship Co. Ltd.; "the earlier doctrine virtually reversed the Constitution" (per Barwick CJ). The Court found that laws with a sufficient connection to the trading activities of constitutional corporations were valid. In addition, the broader conception of the corporations power, that allows for the regulation of any activities of constitutional corporations, was flagged; "I must not be taken as suggesting that the question whether a particular law is a law within the scope of this power should be approached in any narrow or pedantic manner" (per Barwick CJ). Reading down Barwick CJ also gave guidance as