He was mayor of Upper Hutt for 24 years until 2001, and then served three terms on the Greater Wellington Regional Council.
[2] His father, Bill, had worked in banking, then moved to Upper Hutt where he ran a general store in the 1940s, later buying farmland in Whitemans Valley[2][4] where Rex, while mayor, lived and farmed.
[7][8][9] In 2001, Kirton stood as the Upper Hutt representative on the Wellington Regional Council.
[11] He was chairman of the regional council's parks, forests and utilities committee.
[14] Kirton Drive, the main street in the suburb of Riverstone Terraces, is named after him.