[2] He attended Thornlie Senior High School, but dropped out at the age of 17 to work as a furniture removalist.

He spent fourteen years working as an owner-operator before giving up his business to take on a position as an organiser with the Transport Workers Union (TWU) in 1991.

[7] He subsequently decided to make a bid to enter parliament, and in the lead-up to the 2004 federal election, challenged the preselection of veteran senator and former cabinet minister Peter Cook.

Cook was determined to remain in parliament,[8] but withdrew from the ballot of their shared Centre Faction when it became clear that Sterle had achieved enough support to win.

He has served on a variety of Senate and joint-house committees, notably Rural and Regional Affairs, and Transport: Legislation and References.