A dozen independent politicians, including Malcolm Turnbull's successor Kerryn Phelps and Tony Abbott's would-be replacement Zali Steggall, have called for a formal investigation into the Murray-Darling Basin Plan.
Labor has left the door open to supporting the Greens push for a wide-ranging inquiry into the plan's management, with both parties questioning an $80 million water buyback from two properties in 2017.
Energy Minister Angus Taylor co-founded the company that sold the water, but insists he had nothing to do with it since entering parliament and received no benefit from the sale.
A letter by 12 independents, released to media on Monday, calls for a "tough National Integrity Commission" to take immediate action and investigate the water purchase.
"These so-called 'Watergate' allegations of misuse of public funds clearly demonstrate the need for the urgent adoption of a comprehensive National Integrity Commission with retrospective powers," the letter reads.
It was signed by Dr Phelps, who was elected in Wentworth following Mr Turnbull's ousting, Ms Steggall, who is fighting to win the seat of Warringah and outspoken preacher-turned NSW senate candidate Rod Bower among others.
The independents pledged to try to establish a commission with retrospective powers if they are elected in the May 18 federal election.
Prime Minister Scott Morrison hosed down calls for a royal commission into the plan on Monday, defending Mr Angus and Barnaby Joyce, who held the water portfolio at the time.
Australian Associated Press
