More than 200 charities and homelessness services have written an open letter to the federal government urging further funding for wage supplements, which are at risk of running out.
Federal funding for the $65 million equal remuneration order, a supplement to cover wage costs, has been provided since 2012 but will expire at the end of June.
Homeless services have warned the lack of federal supplement would mean 650 support workers would be cut, and more homeless people would not be able to access critical services.
Chief executive of Homelessness Australia Kate Colvin said cost of living pressures had already seen rises in demand for homeless services.
"Families with full time breadwinners can't find a rental and are living in tents. Homelessness services are turning away women and children fleeing violence who desperately need help because they simply don't have enough workers to respond," she said.
"It is untenable that in the midst of our worst ever housing crisis the government is planning to cut funding, and reduce help to people without a home."
Figures have shown homeless services were unable to assist almost 300 people per day during the 2020/21 financial year due to staffing levels.
Of the people turned away, two-thirds were women and children, largely fleeing from domestic and family violence situations.
Australian Council of Social Service chief executive Cassandra Goldie said if the government did not fund award wage increases, services would be forced to cut staff.
"The funding for these 650 jobs runs out in three months and vital community services are now preparing to deliver bad news, both to their women-dominated workforce and also the people they support," Dr Goldie said.
"Of course, all of this can still be fixed. The federal government must urgently lock in this funding to give workers and the people they support certainty about the future."