[2] By the final years of his parliamentary career, Gunn had become the longest-serving member of any parliament in Australia.
After attending Adelaide's Scotch College, Gunn pursued a career as a farmer and grazier in the Mount Cooper area.
Gunn contested the electorate of Stuart, essentially the eastern half of his former seat.
He was the last surviving parliamentarian from the LCL, as well as the last parliamentary survivor of the Dunstan, Corcoran and Tonkin governments.
The Liberals pre-selected former national basketball player Dan van Holst Pellekaan to defend Stuart.