It’s a debate that matters, because population underpins so much that is important in our democracy. From roads and public transport to the number of schools and aged-care facilities our society needs, demography is destiny. Infrastructure, climate change policy, healthcare, national security — if you can think of a big policy issue, the size and age of our population affects it.

But Australia still doesn’t have a formal population policy. As the Government itself has been stressing, there is no formal target for the number of people we think should eventually live here.

Last week Kevin Rudd announced that Tony Burke would become Australia’s very first Minister for Population. You could be forgiven for asking whether Burke wanted the job, given the difficult political terrain he will be asked to navigate.

Barely a week in, Burke has already featured prominently in the news, and been forced to defend Rudd’s now-notorious statement of belief in a “big Australia”. For instance, yesterday he was on the phone to Alan Jones, reiterating the Government’s line that the 36 million by 2050 figure found in the latest inter-generational report is “a projection”, not government policy.

Burke clearly understands the size of the policy challenge that confronts him. “I don’t think either side of politics has ever really grappled with it — and that’s what are some of the limits on the carrying capacity of Australia and whether or not we have the infrastructure in place to be able to deal with a higher population,” he told Jones.

Of course, Australia hasn’t always had an ambivalent attitude to population policy. In the 1940s and 1950s, Australian governments enthusiastically welcomed immigrants to our shores under the rubric “populate or perish”, with schemes for assisted migration such as the famous “10-quid tourists” from Britain.

And in the 1990s, Barry Jones chaired a parliamentary inquiry into Australia’s population carrying capacity: a pioneering study which established for the first time the crucial links between our population levels and the land and water resources required to support them.

But population policy in Australia is inextricably linked to one of our most sensitive political issues: immigration. And, for a range of reasons, immigration shears by Australia’s deepest political fault-lines. Guilt about Aboriginal dispossession, xenophobia and racism, concern about environmental degradation, humanitarian hospitality for refugees and business requirements for skilled labour are all in the mix.

As the popularity of One Nation in 1998 and 2001 in certain parts of the country showed, many Australians are quite uncomfortable with high levels of immigration — despite Australia’s manifestly successful efforts to welcome millions of people to our shores. Population policy is inherently tied up with immigration, and immigration is always going to be unpopular with many people.

The Government hasn’t been helped by the latest inter-generational report, which projects a population of 36 million by 2050. Because 2050 is still 40 years away, the figure looks frighteningly big.

As a recent poll by the Lowy Institute suggests, many of us appear to have contracted a dose of sticker shock, as we contemplate the over-crowded commuter trains and traffic jams our cities already experience. But, in an uncharacteristically sensible article in The Australian, Greg Sheridan points out that the projected population increase is much slower than Australia’s rapid growth after World War II. The media, meanwhile, have been busy reporting that Australians are opposed to our population reaching 36 million so quickly.

While Labor’s strategists must be wondering why Rudd so readily put his hand on his heart and declared his belief in a Big Australia, in the long run this debate is one Australia needs to have. The Coalition certainly appears willing to have it. Under Tony Abbott, the Liberal Party is moving to the right on immigration and population.

The Coalition’s spokesman on immigration, Scott Morrison, has been aggressively attacking the Government almost daily on what he claims are weaknesses in Australia’s border security.

Two days ago, he foreshadowed changes to the Coalition’s policy on refugees, arguing that those claiming refugee status should be required to have documentation. Morrison then twisted the figures to claim immigration was running “out of control” and should be cut back from present levels. It’s the kind of dog whistle politics that plays well to the Murdoch tabloid newspapers, which have been running hard on the issue of boat arrivals all year.

But Abbott and Morrison’s new hawkishness on immigration risks alienating their key business constituency, particularly the mining and resources companies so dependent on foreign labour to staff their plants and mines. As the business lobby’s savvy Heather Ridout countered, there simply aren’t enough Australian mining engineers, doctors, nurses and tradespeople to go around. Curbing immigration will simply cause wages to rise, and interest rates with them.

The Government also hit back hard, pointing out that Morrison had got his figures wrong by including temporary residents in his calculations. As Julia Gillard said on Lateline last night, temporary resident numbers include the “500,000 international students in this country that pay good money to education institutions, generating $17 billion for this economy”.

“Are they saying we don’t want those jobs? Is that the kind of risk that they’re posing for this country?” she said.

It wasn’t long before Morrison was backpedalling on his statement.

For the last two decades — roughly since the controversy over John Howard’s remarks about Asian immigration in the late 1980s — both major parties have elected to pursue a generous migration strategy. This has meant, by and large, that immigration policy has been characterised by a bipartisan consensus that immigration is a good thing for our society.

The Coalition now looks set to abandon that consensus, in the risky pursuit of partisan political gain. It’s a strategy that many will find distasteful. But it could be highly effective.