Before signing the Bar Roll, Greg was an advisor to the Minister for Foreign Affairs (Hon. Mr Alexander Downer MP) between 1996 to 1988. He moved on to be an Analyst with the Office of National Assessments until 2000. From 2000 to 2002 Greg was a Trade Negotiator for the Department of Foreign Affairs and Trade. Greg was the negtiator on the Australia-SingaporeTrade Agreement with the particular responsibility for Trade in Goods and Services, Government Procurement, Custons Co-operation and Dispute Settlement.

Since coming to the Bar, Greg practises broadly in commercial and public law, area's include administrative law (including immigration and freedom of information) constitutional law, contract disputes, trade practices matters, taxation, corporations and securities, equity and trusts and bankruptcy and insolvency.