In short: 

Three millions Australians are "at risk" of homelessness due to increasing rental stress and low incomes, a Homelessness Australia report has found.

It is a 63 per cent increase in the number of people at risk in 2016, and service providers say they are having to shut their doors to new clients due to poor resourcing.

What's next?

It comes as the government weighs a last-minute offer from the Greens to pass two key pieces of legislation is says will improve the housing crisis.

The rising cost of living and rates of rental stress have left about three million Australians at risk of homelessness, a more than 60 per cent increase since 2016, a new report by Homelessness Australia has found.

Homelessness Australia has commissioned modelling of the number of Australians struggling with complicating factors such as low income, rental stress or low social resources, and says people with two or more of those factors are 'at risk' of becoming homeless.

The group's CEO Kate Colvin will launch the report at Parliament House in Canberra today, where she will criticise governments for underfunding service providers experiencing unprecedented pressure.

"Demand for homelessness services has erupted and the system is so under-resourced that people who are homeless can't get in front of a worker who can help them," she told the ABC.

"People who could have afforded private rentals just a few years ago are now resorting to couch surfing, sleeping in cars or pitching a tent."

The Impact Economics modelling estimates that between 2016 and 2022, the number of Australians at risk of homelessness increased by 63 per cent, representing between 2.7 and 3.2 million people.

Ms Colvin said the number today was likely to be even higher.

Victoria and Queensland the fastest growers

A state-by-state breakdown found Victoria and Queensland had seen the greatest growth in people at risk of homelessness, due to rental stress.

In Victoria, 987,405 people were at risk of losing their home, the report found, after the state saw a 23.1 per cent increase in rental stress.

The ACT was the only state to see a decrease in homelessness risk.

Homelessness Australia also surveyed its members as part of the report.

The vast majority reported leaving phone calls unanswered, while 40 per cent were at times having to close their doors to allow time to deal with the clients already waiting inside.

Impact Economics found homelessness service providers were helping about the same number of people each year, but the figures did not show the number of people being turned away because of a lack of staff and resourcing.

Sydney woman Rachael Natoli, who runs domestic violence service provider the Lokahi Foundation, receives no government funding, and is relying on a private benefactor to help her service her three-month-long waitlist.

"It really pisses me off. It infuriates me," she said.

"I feel like the government, both state and federal, aren't taking this matter seriously enough.

"They keep talking about what they're doing, but we're not seeing that funding come through to frontline services."

Ms Colvin acknowledged the Albanese government's increase investment in social housing, but said those homes would take some time to be built and there was still a shortfall of 640,000 social homes.

Housing bills stuck in Senate, with new Greens offer on table

The report lands as the Albanese government struggles to get support to pass two key housing bills, dismissing a last minute offer from the Greens as more about politics than progress.

Labor is entering the final two parliamentary sitting weeks of the year with its Help to Buy bill and Build to Rent bill bogged.

Help to Buy would see the government co-purchase houses with 40,000 first home buyers on low incomes, but has been criticised by the Greens for being small-target policy.

After voting against it for several months, last week the Greens offered their support of Help to Buy if Labor promised to immediately fund more homes under the Housing Australia Future Fund.

The Greens said they would also vote to pass the Build to Rent legislation, if the government increases the minimum number of 'affordable tenancies' in the scheme to 30 per cent of dwellings in each development.

Asked whether the government was considering the Greens' offer, Housing Minister Clare O'Neil did not directly answer, telling the ABC the Greens were politicking.

"With the Greens, it's always about the politics," she said.

"If they were serious about getting an outcome, they'd talk to us, not drop out proposals via the media."

A Greens spokesman told the ABC they wrote to the minister on Friday but had not heard back.

In relation to the Homelessness Australia report, a spokesperson for Minister O'Neil said the government was investing $1.2 billion in crisis housing for women and children.

"This investment is around 20 times more than the investment in the decade prior," the spokesperson said.