WHAT a difference a year makes. This time last year, Melbourne Citymission staff sat down to plan a campaign to put youth homelessness on the public and political agenda. No one, it seemed, cared about Australians left behind in the economic boom — we were all too busy upgrading the plasma TV or buying an investment property in the CBD.

Twelve months on, hardly a week goes by without a story or a speech on homelessness. For the first time in more than a decade, we have a federal government committed to tackling not just the issue of inadequate or insecure shelter, but the complex reasons that lead to people becoming homeless in the first place.

The Rudd Government has now released its hotly anticipated green paper — the first step in the road map to alleviating homelessness.

Homelessness is a complex social issue, with many different strands to the policy debate.

Perhaps the biggest challenge for the Government, as it takes submissions on the green paper, will be shouldering the weight of expectation.

It has been 20 years since a federal government in Australia made any serious attempt to tackle homelessness.

Back then, a ground-breaking human rights inquiry led by Brian Burdekin shamed the political leaders of the day into pouring money into the system.

This money was vital but, ultimately, it had limited effectiveness because it was not accompanied by major policy reform. This time round, homeless Australians — and advocates such as Melbourne Citymission — are hopeful that our political leaders do more than just tinker around the edges.

History shows that ad hoc, piecemeal approaches don't work. Homelessness is more than just "rooflessness". Housing is critical, but it's also important that we recognise that homelessness is often the culmination of long-standing issues related to family violence or breakdown, early school leaving, unemployment, social exclusion, mental illness or drug and alcohol use.

This time, nothing less than a complete systems overhaul across several government jurisdictions and policy domains will cut it.

It's critical the Government's white paper — scheduled for release later this year — tackles failures in areas such as child protection, education, employment and training, and health and disability services.

It is not acceptable, for example, that someone can be removed from an unsafe family environment, spend six years in the protective care of government and, on discharge at 16 or 18 years of age, "graduate" into the homelessness system.

And it's just not right that someone in desperate need of a psychiatric bed ends up in a bunk in a refuge.

The Federal Government's Supported Accommodation Assistance Program — a program that has received significant attention in the green paper — has the potential to drive these changes and achieve genuine policy reform.

SAAP, set up by the Hawke government in 1985, is a dedicated platform for funding and providing homelessness services. It is the only government program in Australia that has homelessness as its organising principle.

There's no question SAAP needs enhancement, to take into account the latest research into the causes, symptoms and consequences of homelessness, but of all the things wrong with the system, SAAP is not one of them. SAAP has been a great platform for working with homeless Australians. With the right investment, it can be the centrepiece of a rejuvenated homelessness system.

Whether the Government keeps the program name, or calls it something different, matters little. What's critical is that the Federal Government retains a dedicated policy and funding platform to deliver services to homeless people.

If we "mainstream" the issue within government — the third option in the green paper — so that each department operates in isolation, delivering a small chunk of services to homeless clients, people will fall through the cracks.

There must be a specialised broker that works across government departments, to ensure that each homeless person gets the services they need, when they need them.

As we await the next step, the Government's white paper, Australia stands at the crossroads. In Kevin Rudd, we have a Prime Minister personally committed to tackling homelessness. In Tanya Plibersek, a federal Housing Minister genuinely committed to making a difference.

It is a once in a generation opportunity to put a real dent in the growing rate of homelessness.

Let's get it right.

Anne Turley is chief executive of Melbourne Citymission.