Mark joined the Electrical Trades Union (ETU) in 1982 and the Australian Labor Party (ALP) in 1993 and has had extensive involvement with both the political and industrial wings of the Labor movement. Mark stood for the ALP in the Division of Cook at the 2004 and 2007 Federal Elections. He was an organiser for the Electrical Trades Union NSW Branch before entering parliament.
Mark was born in Sydney to Maltese parents Victor and Carmen, who immigrated to Australia from Malta in the 1950s. He is married to Anna and together they have a son Gerard. Mark's areas of interest include political philosophy and macroeconomics. He enjoys music, exercise and surfing.