In 1938 he was elected an alderman for the
Municipality of Newtown, serving until the council was abolished in 1948. He served as
Mayor of Newtown for 2 years, from December 1941 until December 1943. Under the
Local Government (Areas) Act 1948, Newtown became a ward of
Sydney City Council and Greenup was elected one of four aldermen, serving until 1 December 1950. The district of Newtown-Annandale was abolished as a result of the 1952 redistribution, and Greenup was defeated in the preselection contest for
Marrickville. Greenup transferred to federal politics as the Labor candidate for the
House of Representatives seat of
Dalley, located in the inner suburbs of Sydney, including
Balmain,
Glebe and
Leichhardt. Greenup was successful at the
by-election on 9 May 1953, but only held the seat until 1955, when he again lost Labor preselection. ==Later life and death==