Labor is now engaged in a high-stakes game in the parliamentary debate on the national anti-corruption commission
The Greens and the Coalition could band together to force a landmark change to the appointment of the national anti-corruption commissioner, in an action the attorney general, Mark Dreyfus, claims could derail the agency's creation.
On Monday, the Greens' judicial spokesman, David Shoebridge, threatened to support a Liberal amendment requiring bipartisan support to appoint a national anti-corruption commissioner unless Labor agreed to put a non-government member on the chair of the Nacc parliamentary oversight committee.
Labor and the Greens are now engaged in a high-stakes game in parliamentary debate on the signed bill, which Alba's government has promised to pass this year.
The Liberal Amendment proposed that the appointment of Nacc commissioners and inspectors would require "at least a three-quarters majority" of all members of the joint parliamentary oversight committee.
Dreyfus said the Liberals had "unfortunately" proposed amendments, including one that he claimed "would create an effective veto against the creation of a national anti-corruption commission".
Labor fears that, if successful, the amendments could create a US-style confirmation hearing process, allowing belligerent opposition parties to refuse to provide Nacc's designation numbers.
"The government will not support the amendment and, indeed, I will ask the Liberal party to withdraw the amendment," Dreyfus told reporters in Canberra.
The Nacc bill and the consequential amendments passed the House of Representatives last week, and will now pass to the Senate where they will be debated on Monday and Tuesday.
Dreyfus said the government "still intends to have this bill passed in parliament this year... so we can continue the long overdue task of implementing [the Nacc].
The Greens have 12 Senate votes, enough to join the opposition to pass the amendment regardless of the views of Labor and other members of the assembly.
Shoebridge said: “Since this law was introduced, the government has learned that a government controlled oversight committee does not have the necessary independence to do its job properly.
"The best solution to this is an amendment by the Green Party which requires the chairman of the non-governmental committee, thereby ensuring the government does not have full control and the opposition does not have a veto," he said.
"If we don't get a number for the Green Party amendment, then moving to a supermajority when the committee votes to appoint a commissioner is a step in the right direction as it removes full control of the government."
"We're not just making the Nacc for the current government, we're protecting it from more dangerous governments in the future who might want to impose the worst commissioners on the Nacc."
The Shadow Attorney General, Julian Leeser, has rejected Dreyfus' claim that "the amendments somehow attempted to veto the creation of the Nacc".
"It was an outrageous slur and we call on the government to withdraw the statement," he said in a statement.
“Our amendment seeks to ensure bipartisan support for commissioners and inspectors.
“This is important to ensure the appointment does not become a political issue.
“We note that the amendments governing the appointment of commissioners with a large majority were also driven by various MPs in the People's Representative Council. No one accuses them of trying to veto Nacc.”
In the lower house independent parliament, Allegra Spender proposed the chairman's vote not count for appointment, meaning the government would need one more non-government vote, while Helen Haines proposed a two-thirds majority.
Spender backed the Greens' position on Monday, telling Guardian Australia a supermajority, or insisting on a non-government seat, were "reasonable" ways of preventing government control of appointments.
"If we get the wrong commissioner, it damages Nacc, and it's very damaging."
Spender said Dreyfus did not want to set a precedent for a non-government seat, but argued "the Nacc is different and committees have different roles".
Jacqui Lambie and David Pocock's network has moved an amendment to remove the "extraordinary circumstances" test for public hearings - which Labor and the Coalition defeated in the lower house.
The bill moves into its second round of reading in the Senate on Monday evening, before a vote on the amendments is likely to take place on Tuesday.