Former deputy primer minister Barnaby Joyce.

Once in a while, perhaps every decade, it pays to listen to Barnaby Joyce.

Until 2018, Joyce was a senior minister of the government, and deputy prime minister for two years. He thus was present, either as a senior figure or in a leadership position, as the Abbott and Turnbull governments undertook major steps toward a police state in Australia.

The establishment of a mass surveillance “data retention” program, successive tranches of counter-terrorism laws that went significantly further than the draconian impositions of the Howard era, police pursuit of whistleblowers who exposed misconduct by government bureaucracies, the creation of a Home Affairs portfolio, attacks on encryption, the use of personal information to smear critics, and police raids on opposition politicians and staff.

Now Joyce, disgruntled and momentarily thwarted in his campaign to seize back the deputy prime ministership, has warned us not to trust the government when it comes to a contact tracing app.

“I treasure the government knowing as little about me as possible,” he told the Nine papers. “There’s always the argument if you’ve done nothing wrong you’ve got nothing to worry about. My argument is if I’m of no concern you need know nothing about me.”

Well put, especially by a man who was part of major decisions that extended the government’s power to know a lot about people who are of no concern.

Joyce’s Nationals colleague Llew O’Brien thinks the proposed app is “Big Brotherish”. Some Liberal MPs also expressed major reservations about its impact.

At the end of last week, the government and its public health advisers were contemplating forcing everyone to put what would essentially amount to government-mandated surveillance malware on the phone of every citizen.

“We start with voluntary and see how that goes,” deputy chief medical officer Paul Kelly glibly declared on Friday, implying that compulsion could follow if insufficient Australians volunteered for the app. Scott Morrison said voluntary downloading was “Plan A” and his preference, but then compared it to “national service”, that these were not “ordinary times” and said “I don’t want to be drawn” on making it compulsory if at least 40% of the population didn’t use it.

By Saturday, the backlash to the idea of compulsory surveillance software on every phone had forced a reversal, with Morrison having to confirm that it wouldn’t be compulsory. Australians can presumably instead expect a colossal guilt trip about not being allowed out of lockdown, and allowing people to die, if they don’t download it voluntarily.

The entire debate about the tracing app is occurring in the abstract, however, because there’s no app to actually examine and only the assurances of politicians like Stuart “Cyber Attack” Robert to consider in relation to who, exactly, will have access to the trove of personal data it would collect, whether security and intelligence agencies will be able to gain access to it (to save lives, of course), how and where data will be securely stored and how much scope for the inevitable mission creep there will be.

We are also supposed to take comfort from the fact that the Australian Signals Directorate, which devotes massive resources to exploiting widely used software to gain illicit access to information, is helping with its development.

But the government has discovered that there is a long-term cost to constructing a police state brick by brick: voters stop trusting you even if you have the noblest of intentions.

Since Barnaby Joyce left the government, of course, it has accelerated its drive to police state status: its prosecution, and relentless harassment, of Witness K and Bernard Collaery, its profoundly flawed anti-encryption laws, raids by its goons on journalists with the purpose of finding evidence about who embarrassed senior bureaucrats, and further prosecution of whistleblowers who exposed war crimes and bureaucratic misconduct.

On this track record, it would be act of madness on the part of any person even vaguely protective of their privacy and basic rights to let this government near their phones, which already generate a steady stream of personal information unless carefully managed.

“Trust us,” says the government. But when someone says not to trust the government of which he used to be deputy PM, it pays to take heed.