People with disabilities will soon discover whether the states and territories back major changes to how their supports are calculated.
The federal government wants to introduce independent assessments for all National Disability Insurance Scheme participants and new applicants.
Disability Minister Linda Reynolds will seek in-principle support from her state and territory counterparts at a meeting this Friday.
The changes are designed to reign in the annual cost of the NDIS, which is projected to reach $60 billion by the end of the decade.
Senator Reynolds argues the cost-cutting measure will also make the NDIS more fair and equitable.
But the proposed changes are strongly opposed by Labor, the Greens and disability community members.
Greens senator Jordon Steele-John accused the government of trying to undermine the scheme and make it more difficult to receive support.
Senator Steele-John cast doubt over the cost projections, calculated by an actuary at the NDIS, and called for the figures to be independently analysed.
"Every time another roadblock is put up to these changes and disabled people speak out about how bad they will be, the government just seems to increase the figure," he told ABC radio.
"It's a scare campaign to get the cross bench and disability ministers to support these changes.
"We are really hoping, as disabled people, that these ministers on Friday do not fall for it."
Senator Steele-John, who uses a wheelchair due to cerebral palsy, urged the disability community to continue fighting the changes.
He described the upcoming disability ministers' meeting as the first in a series of hurdles the Commonwealth would need to clear if it wanted to implement the changes in August as planned.