Federal crossbenchers are being urged to "thrash out" a deal to pass reforms to the NDIS to save taxpayers from a $1 billion bill the delays will cause.
The federal opposition and Greens have teamed up to send the planned NDIS reforms to a second parliamentary hearing, despite a previous hearing recommending they become law.
The reforms, aimed at reining in the scheme's costs, would reduce the number of eligible new participants, as well as changing the criteria for funding.
NDIS Minister Bill Shorten has hit out at the delay, saying the financial costs of the parliamentary dawdling would be passed on to the public.
"I was incredibly disappointed to see that after legislation which has been the subject of a 12-week Senate committee, the Greens and, inexplicably, the Liberals decided they wanted more time to consult over the next eight weeks," he told Nine's Today program on Friday.
"Even though the actuary of the scheme has said that delaying some of these reforms to close down loopholes will cost participants and taxpayers $1 billion over the next 40 days."
Mr Shorten wants the opposition and crossbench to back the changes.
"Rather than let's burn $1 billion on the national credit card, sit down with me and let's thrash it out," he said.
"Let's, for God's sake, not waste $1 billion."
Opposition finance spokeswoman Jane Hume said while the coalition was likely to support the NDIS reform, further scrutiny was needed.
"Stakeholders are coming to us and telling us that they're concerned about how these changes are going to affect them," she said.
"It's much better to do the work now, get the job done, and then pass the legislation rather than find out that there's unintended consequences when it's too late."
While the first parliamentary inquiry recommended parliament pass the reforms, disability groups have criticised the changes.
The annual cost of the NDIS is expected to pass more than $50 billion by 2025/26, higher than the annual cost of Medicare.
The changes to the scheme would be aimed at capping spending growth to the NDIS, with the government estimating $14 billion would be saved under the measures during the next four years.
