Mangerton's Daniel Bourke was not a long-distance runner until last year, when the prospect of an Indigenous Voice to Parliament compelled him to find a way to show his support.
On Saturday, the construction site manager will run 50 kilometres - the distance of an ultramarathon - around 22 voting centres in Wollongong, encouraging others to vote "yes" to the Voice at the polling booth.
"It's really simple: the opportunity for Australia to show proper and final respect for First Nations people by including their acknowledgement in the constitution, and providing an advisory panel to discuss with parliament matters which significantly impact their lives is crucially important," Mr Bourke said of his support.
"It fulfils us as a nation, it provides people currently wondering about their place in the world an enormous sense of pride and hope in the future."
Mr Bourke will set off from Mount Saint Thomas Public School at 8am with Amar Singh, founder of charity Turbans 4 Australia and the 2023 Australian Local Hero of the Year.
He will head south to Port Kembla then northwest to Keiraville, before continuing his circuit through Wollongong back to Mount Saint Thomas.
Along the way he hopes to create excitement and enthusiasm for the Voice - and pick up a few yes votes too.
Mr Bourke is confident his efforts will be received well, no matter what side of the issue people are on, because his is an "open-armed gesture".
So far, he said, every conversation he'd had about the issue had been about the positivity of change for Australia.
"With change comes opportunity, with opportunity comes inspiration, and with inspiration there's no limit to the possibilities of positivity," he said.
Mr Bourke set off on his first long-distance run just before New Year's Eve 2022, completing a marathon in training for the 67 kilometres he planned to run in February.
The latter event was hampered by hot and windy conditions, but he still completed 55 kilometres.
Saturday's run will be his third ultramarathon-distance event in support of the Voice.
Sign up for our newsletter to stay up to date.