Child protection workers say they are only able to care for one in four NSW kids at risk of harm, with the system on the verge of collapse.
Caseworkers walked off the job on Thursday, demanding the state government recruit more staff and fix the embattled sector.
They spoke outside NSW Parliament of exhaustion, escalating industry-wide vacancies and inability to cope.
The Public Service Association warned workers would undertake a series of rolling stop-work meetings across the state.
Secretary Stewart Little said NSW was the only jurisdiction in Australia where all out-of-home and foster care was outsourced to non government organisations.
Private organisations are able to be selective about the children in their care, leaving the most vulnerable at risk, he added.
"It's a disgrace.
"We need a new road map to look at ending privatisation and bringing child protection back into the public sector."
Three in four children reported as at risk of harm from October 1, 2022 until September 30 last year received no visit from caseworkers, according to the latest Department of Communities and Justice data.
A recent report also revealed low staffing is believed to be among the reasons for some of the deaths of children in child protection in 2022.
"That's the real tragedy here," Mr Little said.
The union head and veteran child protection advocate said caseworkers were leaving to work with organisations like Anglicare because the government salary was too low to retain them.
With 1700 vacancies across the state and vacancy rates increasing 250 per cent year on year, Mr Little called on Premier Chris Minns to intervene.
"The most vulnerable kids in this state are at risk of serious harm, or worse, because child protection workers just can't cope, they're understaffed, exhausted and see no other option than to take industrial action," he said.
The government needs to immediately recruit another 500 staff "otherwise the system will collapse".
Outsourced out-of-home care can cost the government upwards of $2 million and urgently needs to be reformed, he added.
Mr Minns said he recognised staff were overworked and dealing with children in desperate circumstances but he didn't have an easy solution.
"If it was simple to sit around the table and work out a change to awards and conditions, then we would do that immediately," he said.
"The problem I've got is that the previous government's reform attempts to outsource much of this work has meant much of it doesn't sit inside the government or on the government books.
"It's going to take a bit of time to get another set of reforms in place so we can get child protection workers that are happy and satisfied in their job."
Mr Little said people who work within the sector know how important every single minute of their work is and "don't take action lightly".
"But they just can't go on as the system crumbles around their ears."
