Housing fund hits wall as crossbench turns the screws

Negotiations on the federal government's key housing proposal are set to drag into budget week as the Greens and crossbenchers push for extra measures to address the housing crisis.

Vulnerable people urgently need a $10 billion housing fund to get over the line in the nation's "single biggest investment" in more than a decade, Housing Minister Julie Collins says.

But the Greens are calling for major amendments to the government's proposal to secure their support, including more rental assistance and one million new homes built to address the housing crisis.

Independent senator David Pocock, who joined the Greens and unions outside parliament for a rally on Tuesday, is also holding out for a more ambitious government plan.

"This is about ensuring that we don't have people having to think about living in their cars," Senator Pocock said.

The Greens are continuing negotiations with the government and movement on the bill is not expected until the next sitting week, which coincides with the federal budget in May. 

Labor's election pledge would finance the construction of 30,000 affordable homes, but the Greens said this would be far outweighed by demand.

With one third of Australians living in rentals, Greens leader Adam Bandt said more assistance was needed. 

"The government needs to act on the rental crisis, there's no guaranteed funding for housing in this bill," he said in Canberra.

"The government is going to put $10 billion on the stock market, and if it makes a return, then some of it may go to housing. Last year, it made a loss ... the government needs to do something for renters now."

CFMEU spokesman Zach Smith said the government needed to spend at least $290 billion over the next two decades on housing, or risk it failing.

"What $290 billion represents is 700,000 houses that are needed for our most vulnerable in society," he said.

Ms Collins said people at risk of homelessness needed the legislation to pass parliament.

"It is the ... single biggest investment in social and affordable homes in more than a decade," she told ABC radio.

Ms Collins said the government was doing its fair share to tackle the housing crisis and issued a blunt message to those opposed to the bill.

"If their response is 'it's our way or zero', that is just unacceptable when you've got vulnerable people on the ground who need housing today."

The fund would be established along with the independent Housing Australia body and a National Housing Supply and Affordability Council, which would provide independent advice.

Census data released last week showed there had been a five per cent increase in the number of Australians experiencing homelessness.

Analysts from the City Futures Research Centre at the University of NSW found 640,000 Australians are in housing stress.

By 2041, that number is expected to be one million.

On Tuesday, St Vincent de Paul joined a growing number of social advocates urging senators to back the government's bill.

National president Mark Gaetani said the plan was "not ideal", but it was a start and must be supported.

"(But) the package before the Senate represents an historic opportunity to start to address Australia's housing and homelessness crisis after neglect and inaction by governments of both persuasions," he said.