Outspoken One Nation senator Rod Culleton has again broken ranks with his leader Pauline Hanson, insisting not only another banking inquiry but also a royal commission must go ahead.
Senator Hanson has told The Courier-Mail newspaper she's won government support for an inquiry over concerns banks are engineering defaults to repossess farms.
But it is far from assured after the prime minister's office said a go-ahead would ultimately be up to the Senate.
It's also understood she hasn't presented the government with any draft terms of reference.
Senator Hanson also told Brisbane radio 4BC she doesn't want a royal commission because Mr Turnbull said it would take years and cost hundreds of millions of dollars.
Senator Culleton told reporters in Perth on Wednesday he was adamant twin probes would proceed.
"Malcolm Turnbull will call a royal commission and if he doesn't, we'll go around him and go for a grand jury or go straight to the top," he said.
"A royal commission cannot be ignored by Malcolm Turnbull because parts of this are civil and parts are very much criminal.
"If he ignores it now ... with what he's got in his lap, would be, I believe, aiding and abetting these banks.
"He's got to let this royal commission run and it will run."
Asked about Mr Turnbull previously ruling out a royal commission, Senator Culleton replied: "Yeah, but that's only one individual. The rest of Australia wants a royal commission".
