Probyn supported deregulation policies while working for the government of Brian Mulroney in the 1980s ("Globe and Mail", 13 May 1986), and continued to endorse energy deregulation throughout the 1990s ("Financial Post", 17 February 1992 and 19 August 1997). In 1997, his firm was involved in the first public-private partnership in Canadian water management in Dartmouth, Nova Scotia ("Financial Post", 23 March 1996). He served on a Market Design Committee established by the provincial Progressive Conservative government of Mike Harris to provide the guidelines for deregulation in Ontario's energy sector ("Hamilton Spectator", 22 April 2002).