In an address to the National Press Club on Wednesday, the businessman said endless population and economic growth was like a “religious faith” for graduates of university degrees in economics and questioning whether these two things were beneficial for Australians was something of a taboo in public discussion.

Mr Smith singled out politicians, economists and journalists for restricting debate about the costs of “endless compound growth in population” and said a Senate inquiry might be needed to break open a conversation.

“It's almost like a religious faith that growth, don't even discuss it, it will just go on forever when it obviously can't and I'm absolutely surprised at that,” Mr Smith said.

Mr Smith said, left unchecked, Australia's population would hit “80 to 100 million by the end of the century if we keep growing”.

He said that kind of perpetual growth would only serve wealthy Australians, while the majority of the population would suffer a decline in living conditions and be worse off.

“The cake is a certain size, mainly coming from our mineral reserves and our primary production from farming, and double the population, I believe everyone's worth half

as much,” he said.

The businessman said Australia needed a plan for sustainable population and economic growth, but gave few specifics of what that management should entail.

He said that was a job for economists and government.

“The Prime Minister wouldn't be game to discuss it, because if he doubted growth for one instant he'd be attacked by anyone,” Mr Smith said.

“I would suggest to him that he says, look, we all know we can't have perpetual growth in the use of resources and energy.

“Don't worry Australians, I'm not going to stop growth, but we all know we can't have it forever so let's get the best experts to tell us how we move to a slightly different system that's sustainable.”

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