Dick Smith, Oliver Marc Hartwich and Tony Burke all have different views on how many people should call Australia home.
We caught up with the three of them to hear their views.
DICK SMITH - UNSUSTAINABILITY
Entrepreneur Dick Smith - a renowned proponent of a small Australia -says the reason politicians don't like talking about population is that the unquestioned demand for economic growth is intrinsically linked to the need for a rising population.
"I think it's only cancer and economists who believe you can have this growth forever."
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He says capitalism can still work well without the insatiable appetite for resources which is required for constant growth, but it's going to require strong leadership. Bringing in migrants to Australia to maintain the status quo would merely result in a 'ponzi scheme', Smith says.
OLIVER MARC HARTWICH - KEEP US PROSPEROUS
Economist Oliver Marc Hartwich is a proponent of keeping Australia's population growing.
Australia is "a country built on migration", says Hartwich.
"We have a chance top keep Australia growing... to keep it a prosperous place."
The ideas cited against a big Australia - such as traffic congestion - can be combated with strong policy, by fixing the federal system and empowering local government.
"Other countries would kill for our problems", he says.
He says we have enough food producing capacity for 100,000,000.
TONY BURKE - NO MAGIC NUMBER
The government's Sustainability Minister Tony Burke says debates over a 'magic number' for Australia miss the point.
The government is more interested in where people live, and how people live. He says he wants to see better government planning lead to more jobs where people live, as a result of good planning.
He says Australia is making strides in terms of energy efficiency, water use and also carbon emissions, but urban sprawl and the general livability of a suburb are things that need addressing.
According to Burke, those who call for immigration cuts ignore the fact Australia is facing a big shortage of labour, as well as some of the other things migrants bring.
'You can end up... under-evaluating the strength of being a strong multicultural society."
