In the week that Australia appointed its first population minister, a survey from a leading Sydney think-tank has shown that Australians are wary of the fast-paced growth of their country.

Right now the population stands at 22 million, but a government study released late last year forecast that it would grow to 36 million by 2050, an increase of 61%.

To put that in perspective, the global population is expected to grow over the same period by 38%, and Australia's projected expansion would likely make it the fastest growing industrialised nation, outpacing even India.

According to the Lowy Institute poll, 72% of respondents support the general principle of a population rise, but 69% want it kept below a 30 million ceiling.

Last year, Kevin Rudd was quick to embrace a Big Australia policy. Now he's having a rethink, ostensibly it seems because he misread the public mood on what has always been a sensitive issue here.

It not only raises the always thorny question of immigration levels, but whether Australia's cities can sustain such rapid growth. The government has refused to set a population target. It says it will report back sometime after the election, which seems like an attempt to neutralise what could be a major issue during the upcoming campaign.

The politics of the Big Australia policy are by no means clear cut. This week the Liberals seem eager to adopt a populist stance. On Tuesday, the party's immigration spokesman, Scott Morrison, said that migration levels were "out of control", and had to be brought "back into perspective". Yet following complaints from business groups, who fear immigration cuts would be followed by skills shortages, he was forced to backtrack. Tony Abbott, meanwhile, says he supports a "strong Australia", which also sounds like a hedge.

We've spoken before about the creep of the cul-de-sacs into the countryside, which looks set to become a headlong rush if the population forecasts. Sydney, for instance, is growing at a rate of over 1,500 people a week, and is suffering badly from an infrastructure lag. Road and rail construction simply cannot keep pace, and nor can new housing. Demand outstrips supply, fuelling Australia's housing affordability problem - a problem exacerbated this week by another hike in interest rates (although, historically speaking, the cost of borrowing remains on the modest side).

The flip-side is that low population growth can lead to stagnation and problems of economic sustainability - in particular, of how to pay for the health and pension costs of an ageing population. Many in the business community equate a Big Australia with a booming Australia. Many in the burgeoning suburbs are increasingly thinking that big is far from beautiful.

UPDATE:

This is also the week, as it turns out, that the Australian government has decided to clampdown on asylum seekers from Afghanistan and Sri Lanka, two of the main source countries. More than 100 boats carrying asylum seekers have been intercepted by the Australian navy since the Rudd government came to power in 2007 and Kevin Rudd has clearly been under mounting political pressure over the spike in the number of boat people.

The government's response is the immediate suspension of visa applications from new Afghan and Sri Lankan asylum seekers. The move is clearly intended as a deterrent to people smugglers who operate mainly out of Indonesia - an attempt to stop the boats. People smugglers will no longer be able to give their Afghan and Sri Lankan clients the assurance that their asylum applications will be processed by the Australian authorities. Instead, there's the much less enticing prospect of being held in limbo at an Australian offshore detention centre at Christmas Island in the Indian Ocean.

The government has said it made the decision in the light of changing circumstances in Sri Lanka and Afghanistan. But the move is widely being interpreted here, of course, as principally a political move designed to neutralise an always sensitive issue ahead of this year's Australian election.

The opposition has repeatedly claimed that the softening of the Rudd government's immigration policies has led asylum seekers to target Australia.

It is always interesting and instructive to put Australia's share of asylum seekers in a global context. According to the latest figures from the United Nations refugee body, the UNHCR, Australia received 6170 applications for asylum in 2009, compared with 1400 the previous year. The United States received 49,020, France 41,980, Canada 33,250, United Kingdom 29,840, Germany 27,650 and Sweden 24,190. On a list of 44 industrialised nations, Australia was ranked 16th overall or, if you prefer, 21st on a per capita basis.

Kate Gauthier of the Refugee Council of Australia bemoans "'the hysterical obsession with each boat arrival" and notes: "It's unfortunate that the most vulnerable people in the world are being treated as public footballs."

Under the new procedures, boats will not be turned away by the Australian navy and boat people will still be taken to a detention centre at Christmas Island, which is already overcrowded. What the Refugee Council of Australia fears is the indefinite detention of new arrivals from Afghanistan and Sri Lanka, who will not be able to apply for asylum for at least the next six months, if they are Afghan, and the next three months if they come from Sri Lanka.

So is this is a paranoiac overreaction or a proportionate response to protect Australia's borders?