Sydney Road, Coburg, wears its remarkable ethnic diversity matter of factly, in the very rhythms of daily life. The shopfronts that line the road - Bollywood Fashions, Afghan Bazaar - provide the backdrop to footpaths populated by faces that bring life to this story: the Muslim father pushing the pram, two young African men sharing a joke as they hurry along.
As if to officially declare its melting pot status, a banner around the corner shouts: "Moreland Council welcomes refugees and asylum seekers". This is the Australian story of a nation built on migrants and newcomers being played out in the everyday routines, joys and struggles of lives being forged in a new home.
Just off this bustling strip is the office of Kelvin Thomson, the Labor member for Wills in the Federal Parliament. Thomson, Coburg-born, has just been re-elected for a seventh term.
It would be fair to assume that Thomson is a supporter of a multicultural Australia, which is true. But Thomson is something of an apparent contradiction: he is also a passionate advocate of cutting net overseas migration, part of a mission to halt population growth and head off the apparent inevitability of a Big Australia - and indeed a Big Victoria, a Big Melbourne.
In August 2009, Thomson stood in the House of Representatives and gave a speech that would set him apart from many of his colleagues, both within and outside the ALP. He argued that Australia needed to "stabilise" its population, nominating a figure of 26 million. Our population is now 23.24 million, and is projected to push well beyond 35 million by 2050. This was a recipe for environmental disaster, he argued,
Thomson would achieve his target in part by cutting net overseas migration to 70,000 a year. The most recent official estimate put it close to 235,000. But Thomson would also increase the refugee program by more than 7000.
We are seated towards the back of a takeaway shop where the house speciality is Mediterranean pizza, and I'm wrestling with the apparent contradiction between this humming multicultural scene and a local MP advocating cuts to immigration.
"It's not about race in the slightest," he counters. "And for anybody who wants this debate to be about race, it's too late. The bird has flown. Australia is a comprehensively multiracial society."
Yet Thomson acknowledges the expectations of how his electorate might react to his views. "I suspect there are a few people out there who expected my electorate would rise up and kill me," he says. "In fact, I've gone through two elections since being very outspoken about this issue without any signs of any difficulties whatsoever."
Instead, he says, his office has fielded calls for support from migrant constituents, who offer this message: "You tell Mr Thomson to keep it up. We came here to get away from what Ankara was or what Shanghai was. We don't want Melbourne to become like the places that we left."
Outside on Sydney Road, a truck driver leans hard on his horn in protest, an angry moment in the crowded traffic as the afternoon peak begins to heat up. We turn around to look. That, says Thomson, is the kind of scene - congestion and resulting road rage - he wants to avoid.
How big should Australia get? How should we encourage or limit population growth? Such questions are largely absent from sustained public debate, despite the fact our swelling population is the engine of much of our economic growth. It's a paradox partly explained by the debate's occasional mugging by racist agendas, and partly by the sheer scale and complexity of the political, social and economic issues involved. As a result, plenty of underlying assumptions and policy shifts are going unexamined.
In Victoria, both major parties accept that Melbourne will get bigger, much bigger, and that growth is good. More people means a greater demand for goods and services, more houses and the creating of more jobs. Grow the population, grow the state.
The Napthine government's recently released Plan Melbourne, which sets the directions for the metropolis and the state until the middle of the century, says Melbourne will need to accommodate 6.5 million people by 2050, requiring another 1.2 million jobs. "While this growth raises challenges, it also holds immense opportunities ..."
The forecast continues a remarkable period of growth in our numbers. Australian Bureau of Statistics figures show we have grown about 2 per cent a year since the turn of the century. In mid-2012, we hit 4.25 million.
With that level of growth, the 6.5 million forecast is looking conservative. If the trend continues, we would overtake Sydney by 2037, and hit 8 million by 2049.
As Plan Melbourne acknowledges, population growth raises "challenges" - although this is probably not the word used by people stuck in traffic or riding sardine-like on trains. The hard reality is that the city needs to deliver the infrastructure and services to support this surge in numbers. Indeed, the new plan, now open for public feedback, is all about developing the city to cope with the increase in population: greater housing density, better transport, more economic activity and jobs.
A plan is certainly a start. But the recent history of the state is that we have failed to cope with the surge in our numbers. Most of our growth has been on the urban fringe, and there is abundant evidence of an alarming failure to provide the services to support these new and largely isolated communities. Without this, we have a planning catastrophe.
The recent report by the Victorian Auditor-General was damning in its criticism of the failure to provide essential public transport and road services to the new communities on the fringe, which in turn threatens access to services and Melbourne's liveability. "Urgent action is needed to address this serious problem," the report concluded.
This is not just a dilemma of the current government, for the boom in population occurred under the watch of the decade-long Bracks-Brumby governments. When Daniel Andrews took over as Labor leader after the Brumby government's defeat in 2010, he conceded Labor had failed meet community expectations as Melbourne's runaway population growth "got away from us".
Today, Andrews doesn't resile from what he says was an honest assessment, although he says he has received criticism from Premier Denis Napthine for making it.
Andrews is a strong supporter of population growth. But he supports a debate about how we manage it. "I welcome a discussion about how we manage population growth and how we protect our quality of life and actually enhance it," he says. "That's a management debate. It does need to be frank."
But, he stresses, "you'll never hear me talk about putting the shutters up. We need to be an economy and a community that grows." Labor, he says, will reveal practical steps to deliver improvements over the next 12 months in areas such as transport and traffic congestion.
Of course, it is our federal government that partly controls population levels through immigration policy. Apart from natural increases - more babies and people living longer - the key is immigration. It accounts for 60 per cent of our population growth.
In the postwar era, the Australian immigration story has been of permanent settlers. Yet over the past decade, there has been a fundamental shift, begun under the Howard government, towards temporary migration.
Despite John Howard's stated and often contentious concerns over multiculturalism, Sydney academic Jock Collins says Howard walked a tightrope, increasing immigration to record levels. In part, this was achieved by switching the emphasis to temporary visa holders with work rights, coinciding with the mining boom. Collins cites a recent Immigration Department report, Australian Migration Trends, that showed temporary immigrants outnumbered permanent immigrants by a ratio of about three to one. They include 457 visa holders, students and working holidaymakers.
"The idea is as soon as the jobs go, the people go," says Collins, a professor of social economics in the UTS business school. Yet there is little data on what happens to temporary visa holders, and whether they do in fact return. "We really know little about it."
Others have taken the rise of the temporary migrant into a wider social debate about their impact on Australian jobs. Monash University's Bob Birrell, for instance, has argued that young local workers are the big losers. "We're well down the track of a dual labour market here," Birrell says. "It's foolish to look at these extraordinary numbers and deduce from that that all's well, and it's an indication of how well the economy's going."
Collins notes what has been a lack of debate over such a fundamental change as the shift towards temporary migration. As he points out, the focus has been on border protection and a few thousand asylum seekers arriving by boat. "That's captured all the oxygen in the immigration debate," he says.
The last serious foray into the broader debate was Kevin Rudd's 2010 declaration in support of a Big Australia, which followed the federal Treasury's Intergenerational Report that predicted Australia's population would rise from about 22 million to 35.9 million in 2050.
There was a brief and often intense discussion about whether growth was good, and Rudd appointed Tony Burke as population minister. That came to an abrupt halt when Julia Gillard deposed Rudd as prime minister, and declared she supported a "sustainable Australia". Burke became minister for sustainable population.
"I don't support the idea of a big Australia with arbitrary targets of, say, a 40-million-strong Australia or a 36-million-strong Australia. We need to stop, take a breath and develop policies for a sustainable Australia," Gillard said at the time. "I support a population that our environment, our water, our soil, our roads and freeways, our buses, our trains and our services can sustain."
This represented a fundamental shift, at least in the political message. Gillard went on to nominate the all-critical western suburbs of Sydney. Ask them about a big Australia, she said, and "they would laugh at you and ask you a very simple question: where will these 40 million people go?"
Collins says it was a very important demarcation for Gillard. "In many ways, some people read that for being a bit of a code for, 'I'm not so much in favour of immigration'." But as Collins points out, there was little change to immigration under Gillard.
The most significant change was passed on the last day of the last Parliament, with legislation tightening the rules for 457 visas passing the Senate, making it a requirement that companies advertise locally first. It was strongly supported by the union movement but condemned by business.
What of the political landscape now? New Labor leader Bill Shorten declared last month he was "ambitious for a big Australia, I am ambitious for more immigration because I think it enriches our country". The sentiment took on a powerfully human and real dimension with the election of Tanya Plibersek, daughter of Slovenian migrants, as deputy opposition leader. Her elevation is a celebration of the classic Australian immigrant story. The last census showed that almost half of us were either born overseas or had a migrant parent.
The position of the new Abbott government on broader immigration policy is yet to take shape. All attention has been on border protection, stopping the boats. On the wider immigration question, Prime Minister Tony Abbott had warned in the 2010 debate that Australian cities were "choking" and that population was growing "in an out-of-control and unsustainable way".
Adding to the policy picture has been new Education Minister Christopher Pyne's promise to make it easier for overseas students who have graduated here to enter the jobs market.
The critical question, then, is this: will Australia finally have a debate about how big it wants to be and, as part of that, the extent of its immigration policy beyond the proportionally small numbers arriving on boats?
On the evidence so far, it appears unlikely. Paul Collins, the historian and former Catholic priest who argues for a sustainable population, says the debate is toxic. "There's this lurking fear that somehow anybody who says that we really need to look at population issues is anti-refugee, is probably racist at heart and certainly doesn't believe in immigration."
"It's a very difficult debate in Australia," agrees Kelvin Thomson. "In some respects, allegations of racism are being used in the way McCarthyism used to be used in the 1950s to close down debate and to smear people who had views that others wanted to disagree with.
"But instead of disagreeing with them through argument and evidence, they've simply disagreed by way of name calling and character attacks."
Thomson is confident he has public opinion on his side, with polls regularly showing two-thirds of people support his view. But that doesn't make for a public debate. Only a few politicians line up on Thomson's side of the debate - most significant among them being former foreign minister and NSW premier Bob Carr.
Thomson says there are others - but they are not prepared to say so publicly. "There are a few more who will talk about these things discreetly in the corridor and say, 'You're right'. But they are unwilling to jeopardise their own political circumstances by saying some of the things that I say."
Thomson attended last week's Canberra conference of Sustainable Population Australia. (Paul Collins is a patron, along with names such as Professor Tim Flannery.) The conference heard from Paul Ehrlich, author of the 1968 book The Population Bomb, a highly contentious work that warned of mass starvation unless action was taken.
At the end of two days, the conference carried a resolution calling for policies to stabilise Australia's population and end coal exports and habitat destruction.
The real question for the conference delegates, however, was if anyone was listening. "The answer is we're whistling in the wind, and nobody is really listening to this message," Paul Collins says. The problem is the message is too abstract, too big, he says. "People can't get their minds around it."
OUT IN FRONT AND BURSTING AT THE SEAMS
■Greater Melbourne had the largest growth of any capital city in Australia, with an increase of 406,600 people in the five years to June 2012, bringing the population to 4.25 million.
■Greater Melbourne grew by an average of more than 1500 per week. Greater Sydney increased by more than 1300 per week.
■The four communities with the largest growth in Australia are on the outskirts of Greater Melbourne, including South Morang (up 25,800 people), Point Cook (19,900), Tarneit (15,300) and Craigieburn-Mickleham (12,900).
■Plan Melbourne predicts a population of 6.5 million by 2050, but that looks conservative. On current trends, 8 million is more likely.
SOURCES INCLUDE: ABS REGIONAL POPULATION GROWTH, AUSTRALIA, 2012, PLAN MELBOURNE.