[1] Murnain was born in Newcastle, to parents Anne and Neil, and grew up in Narrabri in north western New South Wales.
In 2008 Murnain began working at the NSW Labor Party head office as an organiser running campaigns in local, state and federal by-elections and general elections.
[2] With the support of the Australian Political Exchange Council, Murnain undertook an Individual Study Tour of the United States of America in 2012 and aided the Democratic Party campaign.
[6][2] Murnain introduced the Party's first code of conduct[7][8] and announced the introduction of compulsory ethics seminars for newly elected representatives.
[14] Murnain works as a casual academic in psychology at the University of England and as an Associate Partner, Communications at SEC Newgate in Sydney.