Harvey was a founder of one of the country's larger advertising agencies, MacHarman Ayer (formerly MacHarman Advertising), for whom he worked from 1962 to 1992. During this time he was heavily involved in election campaigns for the New Zealand Labour Party between 1969 and 1984. He is credited by many for the physical and political transformation of former New Zealand prime ministers Norman Kirk and David Lange. He also worked as election strategist to Auckland mayors Sir Dove-Myer Robinson, Dame Catherine Tizard, and Colin Kay. Harvey was also involved in the environmental campaign objecting to the building of a hydro-electric power station at Lake Manapouri in 1968 to 1972, the Save Manapouri Campaign. He also produced "The Adventure World of Sir Edmund Hilary", "Keep on the Sunny Side", "Seasons in Nasby" with Warwick Brock and "Start Again" with Roger Donaldson for television. His agency won many international awards for creativity including the first Cannes television award for a New Zealand television commercial (directed by Roger Donaldson). His advertising career spanned some of the most creative years in New Zealand advertising and Harvey attracted and worked with some leading edge talent including Dick Frizzell, John Hanlon, Warwick Brock, Grant Marshall, and Rodney Charters (DOP for the TV series 24). Harvey was an inaugural inductee of the New Zealand Advertising Hall of Fame in 2007.