There are growing concerns about the sustainability of a central Labor policy following new budget projections showing the extent of National Disability Insurance Scheme (NDIS) cost blowouts.
The NDIS was introduced when Labor was last in government, and since returning to power after almost a decade in opposition, the party has remained adamant it will fully fund the scheme.
But achieving that is becoming increasingly harder amid forecasts the program could cost more than $100 billion a year.
The federal budget revealed the NDIS was now second only to debt interest payments as the fastest-growing government payment.
"What we know is that there's a substantial amount of waste in the NDIS," Prime Minister Anthony Albanese said on Wednesday morning.
"This is a very worthwhile program, let's be clear.
"I think it has enormous support. But we need to make sure that it's sustainable in the future."
The budget forecast the NDIS costs would grow 14 per cent a year for the next decade, as the number of people receiving payments continues to outstrip forecasts.
Labor flagged during the election that it would review the NDIS to ensure wasteful spending was stopped.
Since coming to power, the government has established a police task force to hunt down organised crime groups exploiting the NDIS.
That came after allegations members of the Hamzy and Alameddine crime groups in Sydney and other organised criminal gangs have been rorting billions of dollars from the NDIS scheme.
The federal government will spend $24.1 billion to run the NDIS this financial year, with states spending more than $10 billion.
The aged pension is the biggest government social program, costing more than $55 billion this financial year, with the NDIS second.
The states' contribution to the NDIS are fixed, leaving the federal government facing the prospect of picking up the bill for the growing costs in future years.
"I've already flagged with them that it's an issue in which we need to have a cooperative arrangement because of the way that the funding of the NDIS occurs," Mr Albanese said.
"Largely, all of the heavy lifting falls on the Commonwealth rather than states and territories."
People With Disability Australia president Sam Connor said it was important to cut out "unnecessary waste" that had contributed to costs spiralling.
She said it was crucial to ensure the NDIS was sustainable.
"It remains to be seen what will happen for people with a disability and how that will translate to the level of support and funding that people will get," Ms Connor said.
The Coalition has dubbed Labor's October budget a "vanity project" that fails to offer new plans.
Opposition Leader Peter Dutton said the NDIS needed to be more sustainable.
"It is more expensive now than Medicare and if the government had a plan that should have been put in the budget last night," he said.
