He completed high school at Trinity College, Perth, before later being educated at Monash University, from which he graduated with a Bachelor of Arts and Master of International Development and Environmental Analysis.
[4] In 2013, Halse was awarded the inaugural Sam Merrifield prize by the Melbourne Branch of the Labour History Society for his article, 'Citizens who Serve'.
[6] Halse was preselected for the seat Victorian State District of Ringwood in August 2018, following the withdrawal of former Labor candidate Steve Kent.
As a trade unionist, Halse has continually argued for a strengthening of Victoria’s industrial and workplace safety laws publicly and in parliamentary debate.
Reason Party MP Fiona Patten stated Newbury's actions had "dropped to a new low" and noted that ‘when I was first elected here, my partner and I were pretty happy, pretty excited, we may have got a little bit amorous.”[18] On 24 November 2021, Halse announced that he had chosen not to accept the Labor Party’s invitation to stand for office again at the 2022 Victorian State Election.