Welfare groups want the federal government to grasp housing affordability "with both hands", after Prime Minister Malcolm Turnbull appeared to tone down expectations for a solution in the budget.
The Australian Council of Social Service and National Shelter say recent speculation of a government retreat on the issue suggested some within the coalition viewed the task as beyond them.
"It is not," ACOSS head Cassandra Goldie said on Wednesday.
"Australia's housing affordability crisis is serious and we need a serious plan to tackle it. We have become a nation of housing haves and have-nots."
National Shelter chief Adrian Pisarski estimates half a million more affordable homes are needed.
"A growing number of people on social security payments or modest wages are being pushed out of our cities - where most of the jobs are - by a creeping crisis in housing affordability," he says.
In its to-do list, the organisations call for reinvestment in social housing through the National Affordable Housing Agreement with states and backs the government's plan for a "bond aggregator" to encourage private investment in the sector.
They also want the Newstart allowance and rent assistance increased, and secure homeless funding for at least the next five years.
But topping the list are changes to capital gains tax and negative gearing to slow the growth in house prices and rents, and tax concessions changes, which the government is against.
The latest Newspoll published in The Australian found voters backed a reduction in tax breaks for housing investors - including 52 per cent of coalition supporters - compared with 28 per cent against.
However, the Property Council of Australia, which has released a 10-point housing plan - warns against "playing with" negative gearing.
"Negative gearing and the capital gains tax discount are essential components of the private rental market, as well as rational tax policy," it says.
Costly regulations, poor planning decisions and excessive taxes across all levels of government had created a housing logjam.
"Australia is benefiting from population growth, record low-interest rates and relative economic prosperity, but getting so many other policy settings wrong has made affordability worse," chief executive Ken Morrison said.
The PCA wants the government to consider low-deposit loans for first home buyers based on their rental and work histories, as well as a rethink on downsizing rules that discourage pensioners from moving.
The Australian Financial Review reports the government is considering offering exemptions from new limits placed on superannuation to encourage retirees to downsize by selling the family home.