Re Building Workers' Industrial Union of Australia Ex Parte Pillar

This matter concerned an application for a writ of prohibition brought by Pillar Pty Ltd (the applicant) against the Building Workers' Industrial Union of Australia (the respondent union). The applicant sought to prevent the respondent union from proceeding with a claim before the Industrial Commission of New South Wales. The application was heard by Brennan, Gaudron, and McHugh JJ of the High Court of Australia.

The central legal issue before the High Court was whether the respondent union had acted in contravention of section 45D of the *Trade Practices Act 1974* (Cth) by engaging in conduct that had the purpose or effect of hindering or preventing Pillar Pty Ltd from carrying on its business. Specifically, the court had to determine if the union's actions, which allegedly involved preventing its members from working for Pillar and encouraging other unions to do the same, constituted conduct prohibited by section 45D.

The court reasoned that section 45D of the *Trade Practices Act 1974* was engaged if the conduct in question had the purpose or effect of hindering or preventing a person from carrying on their business. The judges considered the evidence presented regarding the union's activities and communications, which indicated a deliberate strategy to disrupt Pillar's operations. They applied the principles of statutory interpretation to the provisions of section 45D, focusing on the objective purpose or effect of the conduct rather than the subjective intentions of the individuals involved. The court found that the union's actions were capable of falling within the ambit of section 45D.

The High Court made orders absolute for the writ of prohibition, restraining the respondent union from further proceeding with its claim before the Industrial Commission of New South Wales.