Among the tens of thousands of marchers at a climate strike in Sydney two weeks ago was an unassuming figure in a hooded sweatshirt and a baseball cap.
It was Mr Mike Cannon-Brookes, who happens to be one of the richest people in Australia.
The 39-year-old co-founder of technology giant Atlassian, who is worth an estimated US$8.4 billion (S$11.6 billion), was joined by numerous co-workers after his firm allowed staff to join the strike as part of the paid week of volunteer leave they get each year.
A vocal critic of the Australian government's climate change policies, Mr Cannon-Brookes said the ruling Liberal-National coalition has no "credible" plan to curb carbon emissions. "Humanity faces a climate change emergency," he told the Business Insider news website. "Businesses and individuals must also play their part, and this responsibility is even more urgent when governments fail."
Mr Cannon-Brookes is not the only company leader in Australia to take a public stance on political and social causes beyond his firm's core commercial activities.
In recent years, corporate bosses have thrown their weight behind some of the most vocal campaigns urging the government to change its stance on issues ranging from same-sex marriage to indigenous rights and climate change.
Several of the biggest firms have weighed in on political debates.
National carrier Qantas was a strong supporter of legalising same-sex marriage during the public vote on the issue two years ago.
Mining giant BHP has been looking to curb its carbon emissions and push for customers who use its coal to also reduce their emissions.
The firm has also taken a stance on indigenous issues, backing calls for a change to the Constitution to give the country's indigenous population input on policy and legislation that affects them.
The ruling coalition opposes the move, claiming it will create an additional chamber of Parliament.
Other companies, like investment bank Macquarie Group, have backed investment in renewable energy and climate change-related projects.
But the ruling coalition has hit back, launching a scathing attack on company leaders, accusing them of ignoring their obligations to shareholders and employees.
Mr Ben Morton, Assistant Minister to the Prime Minister, said companies should campaign on topics such as tax or industrial relations rather than social issues.
"Too often I see corporate Australia succumb or pander to similar pressures from noisy, highly orchestrated campaigns of elites," he said in a recent speech at an Australian Chamber of Commerce and Industry event.
Prime Minister Scott Morrison backed Mr Morton's call, saying firms should focus on their employees and avoid "distractions".
The attack has prompted debate about whether companies have a social responsibility or should focus only on profits.
Some commentators and business leaders pointed out that firms can do both - and that backing carefully selected messages can be good for branding.
Qantas chief executive Alan Joyce said Mr Morrison's demand for firms to keep quiet was anti-democratic. He said the majority of younger staff want to work for socially conscious firms, and many travellers prefer flying with airlines whose brands they support.
"We're not going to pull back on what we say on social issues, because that's important to our employees, our customers, our shareholders," Mr Joyce told the National Press Club this month.
Questioning such an approach, Mr Tom Switzer, executive director of the Centre for Independent Studies, said companies risk damage to their brands and reputations by entering the debate on divisive and politically charged issues.
"When companies lose their focus, they will see the quality of their products diminish. Markets have a way of dealing with underperformance," he wrote in The Sydney Morning Herald.
Australians appear to support the right of company bosses to speak out, but are sceptical about their motivations.
A recent opinion poll by the Committee for Economic Development of Australia found that 78 per cent of people supported business leaders speaking out on social matters.
However, 52 per cent thought that they do so to support the interests of their own companies.