Greg is a barrister and writer. He is former National President of the Australian Lawyers Alliance and practices in the areas of criminal law, family law and administrative law.

He is a former senior political adviser and the author of 3 books on Australian politics. He ran the 1999 Republic Referendum campaign and was National Chair of the Australian Republican Movement from 2000-02.  

Greg is a weekly columnist with the Hobart Mercury and writes regularly for other outlets. Greg is also an adviser to Wikileaks and Julian Assange. He is a Spokesperson for the Australian Lawyers Alliance.

While National President of the Lawyers Alliance he advocated legalization of drugs and has consistently called for drug policy based on evidence.