The banking royal commissioner, Kenneth Hayne, has delivered a withering criticism of the state of Australian politics, saying trust in governmental and private institutions has been “damaged or destroyed”.

In his first public comments since handing down the royal commission’s findings, Hayne said the country’s “opaque” decision-making processes were seen by the public as “skewed, if not captured” by powerful vested interests, while leaders were “unable to conduct reasoned debates about policy matters”.

Instead, Hayne said, they resorted to the “language of war” and sought to “portray opposing views as presenting existential threats to society as we now know it”.

“Reasoned debates about issues of policy are now rare,” he said. “Three- or four-word slogans have taken their place.”

Hayne, a former high court judge, made the comments in a speech in July that was only published on Wednesday.

Kenneth Hayne with treasurer Josh Frydenberg in February. Photograph: Kym Smith/AAP

His royal commission is among several that have been established in recent years. At the federal level, a royal commission into aged care is now under way and the Morrison government has also established another into abuse in the disability sector.

“Notice how many recent inquiries relate to difficult issues of public policy: how can we, how should we, look after the aged? How can we, how should we, respond to mental health?” Hayne said.

“Some are more particular. Has the course of criminal justice been deflected by the way in which a lawyer provided information to police?

“Does reference of matters of these kinds to royal commissions suggest that our governmental structures can deal effectively only with the immediate spot fire and cannot deal with large issues?”

And he warned that the trend should not be “dismissed as some passing fad or fashion”.

“Instead, we need to grapple closely with what these calls are telling us about the state of our democratic institutions,” Hayne said.

“Trust in all sorts of institutions, governmental and private, has been damaged or destroyed.”

In a speech which criticised all sides of politics for what he viewed as increasingly partisan rhetoric, Hayne singled out debate around the Uluru Statement as an example of the declining standards of public discourse.

Hayne argued that public debates proceeded by “reference only to slogans coined by partisan participants”.

“We have seen that in this country in the debate about the Uluru Statement from the Heart,” he said.

“We have seen that in the United States in the debate about the Mueller report. The examples can be multiplied.”

Opponents of the proposal for constitutional recognition have sought to incorrectly portray the call for a voice to parliament as a “third chamber”.

The former deputy prime minister, Barnaby Joyce, recently apologised for using this description of the proposal, admitting he was wrong.

In an apparent shot at the media, Hayne also said that “commentary focuses on what divides us, rather than what unites us”.

Hayne’s final report into the banking sector was handed down in February. He made 76 recommendations.