South Australian Premier Jay Weatherill is vehemently opposed to the Murray-Darling Basin Authority's (MDBA) third draft plan, released on Monday, and has threatened to launch a High Court challenge if environment minister Tony Burke signs off on it.
Mr Burke says he will continue to negotiate with the basin states on the plan.
"But I reserve powers to be able to sign off on a final plan, even if I don't believe we've got the agreement of the states," he told the Ten Network on Sunday.
He added he hoped that wouldn't be the case.
Asked if he was confident the plan would withstand a High Court challenge, Mr Burke said he was.
"The latest version that has come out is an improvement," he said.
"They (the MDBA) have fixed some of the ground water problems that I was concerned about."
Additional improvements would be added to a final plan.
The plan that was released on Monday followed 20 weeks of consultation with communities and stakeholders.
It includes more than 300 changes, including new provisions, but does not propose changing the water recovery target of 2750 gigalitres per year.