Former Turnbull government minister Fiona Nash has admitted the coalition got it wrong in not calling a banking royal commission sooner.
Ms Nash, who was forced out of parliament during the dual citizenship saga, joined other Nationals colleagues in offering the concession.
"I was in government at the time, I think we got it wrong," Ms Nash said on ABC's Q&A program.
"I think we should have done it sooner.
"Australian people intrinsically want to see things be fair and I really do think we should have done that sooner than we did when I was in government."
Her admission follows former deputy prime minister Barnaby Joyce's, as well as cabinet minister Matt Canavan - who too admitted he was wrong.
His colleague Mathias Cormann says the government had genuinely believed, before announcing the royal commission, that there had been enough inquiries into the sector and it was time for action instead.
But "with the benefit of hindsight" the inquiry should have been called earlier, he told Sky News.
One Nation leader Pauline Hanson welcomed Prime Minister Malcolm Turnbull saying it was a political mistake not to call a royal commission sooner.
"Let's get on with the job now," she told ABC TV on Tuesday.
"It's no good going over it and over it."
Senator Hanson wants the banks to cover the cost of the royal commission instead of the taxpayer and for it to be extended to liquidators and mortgage insurance.
Senator Cormann, who is in Berlin with Mr Turnbull for talks on security and trade, says he's been "surprised" at the revelations unearthed by former High Court judge Kenneth Hayne.
But the royal commission should be allowed to do its work before anyone jumped to conclusions.
"You can't make a blanket statement across the board," the minister said.
"Obviously the royal commission is working through what's what and who's done what, and to the extent there is wrongdoing, people have to have the book thrown at them."
He took aim at politicians who have suggested all banks should be penalised by not allowing them the benefits of a corporate tax cut.
Asked about former prime minister Tony Abbott's call for regulators to be sacked for not doing their job, the minister said the government would be making "considered judgments" at the end of the inquiry.
Australian Associated Press