Labor’s NDIS overhaul faces delay as Coalition and Greens consider teaming up to slow bill’s passage

The Greens want Labor to halt its plans to rush NDIS cuts through the Senate later this month, urging a longer inquiry process as the government seeks the minor party’s support for its contentious tax and housing changes.

It opens the possibility of the Greens and Coalition teaming up in parliament to support extending separate Senate inquiries into both the changes to the national disability insurance scheme and tax proposals, thereby delaying Labor’s hopes of passing those bills before the end of June.

While the Greens are inclined toward supporting the changes to negative gearing, capital gains tax and family trusts, and voted for the legislation in the lower house on Thursday, senior party sources say they do not believe the government has made the case rushing those changes through parliament.

The shadow treasurer, Tim Wilson, said the Coalition would seek “maximum leverage” to scrutinise the tax changes, not ruling out seeking the Greens’ support to have a longer inquiry. The Greens treasury spokesperson, Nick McKim, said his party opposed the NDIS changes and were hoping to further probe those cuts.

“The Liberals have effectively said that they’d be open to a longer inquiry on the NDIS, that’s if they get a longer inquiry into the tax package,” he told the ABC.

Sign up for the Breaking News Australia email

“Obviously they’ve made that position public, and of course we’re thinking about that.”

The Greens and Liberals together would have the numbers in the Senate to extend those inquiries.

Guardian Australia understands the Greens have told Labor it would be a “red line” for them if the NDIS bill was pushed through parliament in the next sitting fortnight, beginning 22 June. The government wants the NDIS changes and its first budget bill to be passed by the Senate before parliament rises on 2 July for a winter recess.

The Greens have long supported moves to wind back negative gearing, CGT and family trust concessions, and while the leftwing party wants the government to go even further in its proposals, it is unlikely to vote against that budget legislation. The Greens’ sole lower house MP, Elizabeth Watson-Brown, voted for the bill in the House of Representatives on Thursday, and both Labor and the Greens say negotiations are progressing constructively.

But Coalition MPs are angry at the haste with which Labor wants to pass the tax bill, and the Greens have similar concerns about the NDIS changes. While the Coalition backs the NDIS changes and the Greens will likely back the tax bill, they may both support longer inquiries into both bills.

McKim admitted the two bills concerned “two very disparate issues”, but that his party “want to do everything we can to protect people from the NDIS attacks”.