John Toohey Chambers
Greg went to the Independent Bar in Western Australia in 1993 and was appointed Senior Counsel in 2002.
He was made an Adjunct Professor of Law in 2001 at the University of Notre Dame Australia. Since 2000 he has regularly taught a course in Indigenous Peoples and the Law at the University of Notre Dame Australia and in 2011 at the University of Western Australia
COMMERCIAL LITIGATION AND INSURANCE
Greg's current practice includes commercial litigation (e.g., UGL Engineering Pty Ltd -v- Complete Power Solutions Pty Ltd  WASC 211) and insurance law (e.g.,Ward v Metlife Insurance Ltd  WASCA 119).
ENVIRONMENT PLANNING AND HERITAGE
In 1990, while Principal Legal Officer of the Aboriginal Legal Service of Western Australia, Greg appeared as Counsel in the High Court in Bropho v Western Australia  HCA 24, a case which determined that the Aboriginal Heritage Act (by implication) bound the Crown. Greg's practice at the Bar continues to include that area of law, along with related Environment and Planning law; and featured a large body of litigation between 2005 and 2007 over a permaculture development based on a survey-strata plan in the South of the State, (e.g.,The Owners of Rosneath Farm – Strata Plan 35452 and Rowell & Anor  WASAT 95).
Greg practised as a sole practitioner between 1983 and 1988 in Cairns, North Queensland and half of his practice was in family law, mostly referred from Women's Shelters. His current practice includes family law (e.g., Stanford v Stanford  HCA 52 submissions on a property alteration order, the Family Law Act and the Constitution; a parenting and costs case:  FCWA 28; and a restraining order appeal: Baron v Walsh  WASCA 124).
Greg was appointed as an Inquirer under the Local Government Act, with the powers of a Royal Commissioner, to inquire into the City of South Perth (2001-2) and the City of Joondalup (2004-5) with his reports resulting in the dismissal
of the elected Councils for failure to provide good government. He continues to practice in the area of local government (e.g., Minchin & ors v Town of Claremont  WASAT 338)
Greg was a founding Committee member of the Aboriginal Legal Service of Western Australia as a student in 1973-4. His first employment as an admitted practitioner was with the ALSWA in 1976-8 in Kalgoorlie and Perth and he also worked in Aboriginal Legal Services in Cairns, North Queensland from 1981-83 where he was mainly involved in Criminal defence advocacy. He continues to act in occasional criminal trials.
Between 1978 and 1980 Greg completed a Research project, funded by the Australian Institute of Aboriginal Studies on the topic "Aboriginal Land Rights at Common Law" and in 1982 issued the writ in the High Court in Mabo v Queensland HCA 23 . He had the conduct of that case to its completion, ultimately appearing as counsel for Eddie Mabo in the High Court. A substantial part of his practice at the Bar has been in native title.
In 1982 he was the instructing solicitor in Koowarta v Bjelke Petersen  HCA 27, in which the High Court determined that the Racial Discrimination Act was a valid exercise of the external affairs power under the Constitution. Another significant area of practice for Greg at the Bar has been in racial discrimination and racial vilification matters (e.g., Clarke v Nationwide News Pty Ltd trading as The Sunday Times  FCA 307); Sexual Discrimination and Sexual Harassment (e.g., Ashton v Wall & Beechers Pty Ltd (1992) EOC 92-423,447,488); Disability Discrimination (Burns v Education Department of WA  FCC reserved decision) and numerous refuge cases. In 2009 he received the Law Award from the Australian Human Rights Commission.
Between 2009 and 2013 Greg represented a personal injuries lawyer in relation to allegations of professional misconduct (Legal Profession Complaints Committee -v- O'Halloran  WASC 430;  WASAT 95) and has represented several legal practitioners since, e.g., Legal Profession Complaints Committee and Bower  WASAT 47 (currently the subject of an appeal)
Since 2009 Greg has been briefed in numerous Workers Compensation and Motor Vehicle Accident matters, appeared in the appeal: Christos -v- Curtin University of Technology  WASCA 110; and represented the Plaintiff in the medical negligence case of Stobart v Al Hakeem  WADC 127.
In 2013 Greg was Counsel for the Plaintiffs in Collard v Western Australia  WASC 455, a test case for Western Australia on the application of a fiduciary duty of the State to the 'Stolen Generation' of Aboriginal people in WA.
John Huelin Memorial Human Rights Day Lecture 1990: Aboriginal Heritage: Bropho v WA
2016 Sir Ronald Wilson Lecture: The High Court: Legal Answers to Contemporary Political, Social and Administrative Issues https://www.youtube.com/watch?v=b4vqByU8N3M
John Toohey Oration:The Toohey Legacy: rights and freedoms, compassion and honour