He was a member of the New South Wales Legislative Assembly from 1953 until 1983 and represented the Labor Party.
Born in the Sydney suburb of Marrickville, Crabtree was the son of an engineer, and was educated to intermediate level at Kogarah High School.
He joined the ALP in 1931 and worked as a public servant initially for the New South Wales Government Railways.
Later he served as an office-holder in the Australian Railways Union and the private secretary to Clive Evatt from 1947 until his entry into parliament.
[1] Crabtree defeated Douglas Cross the incumbent member for the seat of Kogarah, at the 1953 election.