Every so often political leaders give speeches that address the great issues of their times, and in doing so define their own values and crystallise perceptions of their personal characters.

Take Lincoln’s 272 perfectly chosen words at Gettysburg, or Churchill’s World War II appeal to British stoicism: “We shall fight on the beaches”. Or Barack Obama’s nuanced “A More Perfect Union” dissertation on race in America, Ronald Reagan’s Berlin entreaty – “Mr Gorbachev, tear down this wall” – or Robert Menzies’ “Forgotten People” speech.

Scott Morrison gave such a defining speech last week when he addressed the greatest issue of our time: climate change. And he encouraged the polluters to pollute more and committed his government to finding new ways to punish those who would stand up against the polluters.

His speech to the yearly lunch of the Queensland Resources Council, a group largely made up of fossil fuel interests and companies that service them, is already being widely seen as definitive of the man: belligerent in rhetoric, authoritarian in tone, divisive in intent, unimaginative in vision, deceptive and insubstantial in content.

The language was strong. Morrison warned his audience: “A new breed of radical activism is on the march. Apocalyptic in tone, [it] brooks no compromise, all or nothing. Alternative views not permitted.”

City-based activists, he said, were “sneering” at working people in the regions, and intent on destroying their livelihoods.

“Absolutist activism” and “anarchism”, he called it, manifested in disruptive street protests, or in acts of trespass and vandalism. Even more “insidious”, though, was an escalating trend of environmental groups targeting businesses they didn’t like with boycotts.

As a result, Morrison said, “some of Australia’s largest businesses are now refusing to provide banking, insurance and consulting services to an increasing number of firms who just [provide] support through contracted services to the mining sector and the coal sector in particular”.

“Protest does not prevent trade or commerce, and we all have the right to call on other people not to spend their money with businesses of which we disapprove.”

He categorised action of this type as “secondary boycotts”, and assured his mining audience, “This is not something my government intends to allow to go unchecked. Together with the attorney-general, Christian Porter, we are working to identify a series of mechanisms that can successfully outlaw these indulgent and selfish practices.”

Morrison directed his threats not only at protesters who chain themselves to mining equipment or engage in other acts of civil disobedience – actions for which legal sanctions already exist. He was, in the words of Professor Kate Galloway, who is an expert in property and consumer law at Bond University, threatening to make illegal “the simple exercise of consumer power through public advocacy”.

Professor Galloway tells The Saturday Paper that such exercise, and even peaceful protest against companies, does not fit within the long-established definition of a secondary boycott. Under section 45D of the Competition and Consumer Act (CCA) 2010, a secondary boycott is defined as conduct that prevents the supply of goods or services to a person, causing substantial loss or damage to a business. The legislation includes a specific exemption for consumer or environmental boycotts.

The secondary boycott laws, she says, go back decades to the days of the Fraser government and the desire to stop unions from blockading businesses.

“You can understand that,” she says. “If the wharfies wouldn’t unload goods off the dock, that is a clear example of a secondary boycott.

“But protest does not prevent trade or commerce, and we all have the right to call on other people not to spend their money with businesses of which we disapprove.”

Indeed, that right is now exercised more often than ever.

“These days,” says Galloway, “you get an app that tells you whether Target or Sportsgirl or Myer or whoever uses sweatshop labour in making the clothes they sell. We now have a rating system on Google My Business. What if you go on and write them zero stars?

“Christian Porter is a smart guy, a pretty switched-on lawyer, but I find it really difficult to believe that there is a viable means of regulating this.”

On October 3 this year, Sydney radio shock jock Alan Jones went on air and delivered payback to one of the scores of companies that had pulled their ads from his program following his misogynistic comments directed at New Zealand Prime Minister Jacinda Ardern.

His target was the supermarket giant Coles. The people who wanted to “occupy the high moral ground” on the Ardern issue, he fumed, were “corporate hypocrites”.

“Is this the same mob who have been ripping off dairy farmers by screwing down the processor who then screwed down dairy farmers on the farm-gate price?” he said. “Is this the same Coles?”

Jones called for his listeners to boycott Coles, much like activist groups – principally one named Sleeping Giants – had called on advertisers to boycott his show.

“We can both play the same game,” said Jones. “So, I can tell my listeners to give Coles supermarket and their petrol stations a very wide berth.”

Jones was not the first to make the call against Coles, either. In an interview on 2GB back in February, Water Resources Minister and Nationals MP David Littleproud invited consumers to “vote with their wallets” and “stick it up these guys”.

So, which of these amounts to a secondary boycott?

Professor Graeme Orr, an expert in the law of politics at the University of Queensland, suggests that while Littleproud may be in the clear, Sleeping Giants may not.

It depends, he says, on whether the threat of a boycott is directed at a primary or secondary target.

“The Sleeping Giants example is a good one,” Orr says, “because in a sense they’re not targeting Jones. They’re trying to put pressure on someone who’s an intermediary – the meat in the sandwich – in this case, the advertisers.”

But it’s a hard line to draw. Jones’s tirade also targeted milk processors – although he didn’t name them – who are the intermediary between Coles and dairy farmers. And what about the case of George Christensen, another Nationals MP, who has called for a boycott of Ben and Jerry’s ice-cream because of its opposition to the Adani coalmine in Queensland? Can such a reactive boycott be considered a secondary boycott?

Like Galloway, Orr questions the government’s ability to legislate in this area: “It’s one thing to say it’s an offence to try and incite others to commit a clear wrong, like invading property or property or trespass, but quite another to go after people just for encouraging other people to think about social values when they make commercial decisions.”

He poses the question: “What about non-quiet shareholders?”

This government has tried before – and failed – to stifle dissent in this way.

“Under Tony Abbott,” says Galloway, “the government asked the Harper review of competition policy to examine whether environmental protests could be classified as secondary boycotts. Harper found not one example of a secondary boycott. It characterised what was going on as public advocacy.”

“In the absence of such evidence,” the Harper report said, “the Panel does not see an immediate case for amending the exception [to section 45D].”

The Saturday Paper contacted Ian Harper, now dean of the Melbourne Business School, about the government’s renewed attempt to legislate against environmental boycotts. He reiterated his conclusion in his reply: “Submissions to the review made it clear that, absent an exemption on environmental and/or CP [consumer protection] grounds, an outright ban on secondary boycotts could set the CCA in tension with common law rights to protest and perhaps contravene the broader public interest in doing so.”

Paul Oosting, national director of GetUp!, perhaps the government’s least favourite progressive activist group, sees the prime minister’s latest threat as part of a wider effort to silence dissent.

“Morrison talks about quiet Australians because he wants Australians to be quiet,” says Oosting.

“This is a government that raids media outlets, seeks to crush whistleblowers, shut down unions, silence people seeking to engage in political debate through a whole range of mechanisms.”

He continues: “I think last week’s speech was a defining one. [Morrison] made it quite clear he is a populist, authoritarian leader. He set out to try and pit cities against regions, workers against workers, and he showed his intention to take away free speech and democratic rights and deliberately divide the country.”

The speech certainly divided Australia’s leaders in business. Some Liberal Party loyalists and leaders of fossil fuel companies applauded him. But Mike Cannon-Brookes, billionaire co-founder of the tech company Atlassian – who is reinvesting hundreds of millions in low-carbon ventures and renewable energy ventures – accused Morrison of threatening Australia’s future.

“The government can’t legislate to stop the decline of coal and the rise of solar and wind,” said Cannon-Brookes. “Shutting down debate is a strike against our democracy. Instead of attacking people who just want good policy, we should look at the upside: Australia can be a winner in a carbon-constrained world.”

David Ritter, chief executive of Greenpeace Australia, views Morrison’s speech as essentially a piece of theatre, and the threat of punitive new laws as an attempt to distract from the government’s inability to offer solutions to “a wide range of massive structural problems facing Australia”.

He ticks some off: a stagnant economy, falling living standards, rising power prices, price-gouging banks, a crisis in aged care, general stress and social anxiety in the community and, above all, the existential threat of climate change.

“It almost seems that, in the absence of any positive agenda, the one central organising principle for the Coalition government has become the defence of the fossil fuel industries,” Ritter says.

In his Twitter feed this week, Ritter posted links to two powerful statements, one being the Morrison speech. The other was a piece published a few days later in the journal BioScience and signed by more than 11,000 climate scientists.

The scientists were unequivocal: the world is facing a climate emergency and without an immense increase in our efforts to address it, including the abandonment of fossil fuels, we all face a future of “untold suffering”.

They made their case with a wealth of empirical data – in stark contrast to Morrison, who made his with populist rhetoric and hollow legal threats.

Ritter posed a simple question: Who will you believe?