Federal government changes to the way water in the Murray-Darling Basin is distributed could be shot down in the Senate on Wednesday.
The coalition only has hours left to find the numbers to stop a disallowance motion - spearheaded by the Greens and supported by Labor and the Nick Xenophon Team (NXT) - from blocking changes to the Murray-Darling Basin Plan.
"This is the insanity of the situation in which we find ourselves, that the Greens and Labor party are prepared to put South Australia at risk," water minister David Littleproud told ABC radio on Wednesday.
The Greens tabled two disallowance motions, one of which must come to a vote today or the government's proposed changes would be deemed disallowed.
The government was furiously negotiating with Labor, urging them to abandon the Greens' motion and support proposed changes to the basin plan, which would see a reduction in water recovery.
Labor issued a list of conditions - including corruption, consultation, and environmental concerns - for the government to meet if they want their support.
But the opposition of Victorian Labor to the disallowance motion and the South Australian state election also complicated federal Labor's position on the issue.
"We can't have more revelations of the problems that are there," Labor senator Doug Cameron told reporters in Canberra on Wednesday.
Greens senator Janet Rice said negotiations were ongoing but could not guarantee that Labor support would hold.
"But there are no jobs on a dead river," she said.
On Tuesday, NSW and Victorian water ministers, Niall Blair and Lisa Neville, said they would pull out of the basin plan if the Turnbull government's proposed changes were not passed in the Senate this week.
NXT senator Rex Patrick said that move was "disingenuous".
"The solutions just need time and the disallowance motion on the Northern Basin Review gives us that time," he said in a statement on Wednesday.
"What a shame it's come to this."
Senior researcher at the Australia Institute, Maryanne Slattery, said the amendment would allow decisions to be made without any scientific or socio-economic analysis.
"While there has been much publicity of the reduced water recovery in the Northern Basin, there has been no public discussion of this provision," she said in a statement.
"This amendment would allow the states and MDBA to change water extraction limits between valleys without reference to the communities or the health of the river."
Senator Rice said the government needed to ensure decisions were being made with proper process and parliamentary oversight.
"We're in this mess because big irrigators upstream have stolen water. There hasn't been transparency," she said.
Cross bench senator Derryn Hinch said he was leaning towards supporting the Greens on their first disallowance motion.
"But on the big picture, I'm not throwing the baby out with the bathwater," he said.