Malcolm Turnbull says in hindsight it would have been better for the Government to have set up a banking royal commission two years ago.

Key points: After two years of argument, the Government called a banking royal commission late last year

After two years of argument, the Government called a banking royal commission late last year PM says he should have established one sooner, having now seen some of the evidence to emerge

PM says he should have established one sooner, having now seen some of the evidence to emerge He has not apologised, but explained why he waited

Mr Turnbull and his senior colleagues have spent the past two years arguing against holding a royal commission into the financial sector, although some of his backbenchers were campaigning vigorously for a royal commission to be held.

The PM finally called a royal commission late last year and the shocking revelations have emerged as it has been taking evidence.

Mr Turnbull has taken responsibility for not calling the formal inquiry earlier.

"Politically, all of the commentators are right when they say we would have been right to establish one earlier," Mr Turnbull said overnight while on a visit to Germany.

His position is at odds with the Financial Services Minister Kelly O'Dwyer, who yesterday repeatedly refused to acknowledge the inquiry should have been established earlier.

Sorry, this video has expired Kelly O'Dwyer avoids saying delaying RC was a mistake on Insiders

Resources Minister Matt Canavan today said he was wrong to have resisted the banking royal commission for so long.

He said he has been disgusted and shocked by the evidence that has been presented.

"I am happy to say I didn't think a royal commission was going to deliver the results that it has and therefore, yes, I am happy to say I was wrong," Senator Canavan said

Treasurer Scott Morrison conceded the Government has "copped a lot of political flak for not taking the decision to go to the royal commission earlier".

But Mr Morrison avoided questions about whether the Government had been wrong to delay calling the inquiry.

Wiliams shocked at evidence despite longstanding push for inquiry

Nationals senator John 'Wacka' Williams is one of those who was insisting for years that a royal commission was necessary.

He said those who previously opposed the inquiry should now do as former Nationals leader Barnaby Joyce has done, and admit they were wrong.

Senator Williams said despite his long-standing insistence that a royal commission was needed, he was still shocked at the evidence that has been given about wrongdoing.

He also said he expected more scandals to emerge as the commission continues.

While Mr Turnbull conceded it was wrong politically to delay setting up the royal commission, he had not apologised and instead moved to explain why he had waited.

The PM said he had "called out the unacceptable behaviour of the banks in a speech two years ago".

"I talked about how there had been a failure to put customers first and that the culture of the financial services sector was not delivering on their fundamental fiduciary obligation to put the customers first," Mr Turnbull said.

He argued that it would have been harder to make immediate regulatory changes to the sector if a royal commission was underway.

"My concern was that a royal commission would have gone for several years, that has generally been the experience, and people would then say 'you can't reform, you can't legislate, you've got to wait for the royal commissioner's report'."

He said it was better that there had been changes made over the past two years, including toughening penalties, strengthening ASIC and setting up a one-stop shop for consumer complaints.

One Nation leader Pauline Hanson insisted the Government should recover the cost of the royal commission from the banks.

She said it had cost $70 million so far and she had spoken to Finance Minister Mathias Cormann urging him to get all that money back from the institutions, "no questions asked".

Senator Hanson argued that the Government should quarantine the banks' share of any company tax cuts until they have fully compensated victims.

She also called for the scope of the inquiry to be broadened to include liquidators and receivers as well as extending it to cover mortgage insurance.

Former prime minister Tony Abbott called for financial regulators to be sacked for not carrying out their duties thoroughly enough.

He told 2GB all the existing regulators should be sacked and people who are "much more vigilant and much less complacent" put in their place.

"If the police are turning a blind eye to the criminals, well, you have got to get rid of the police and get decent people in there," Mr Abbott said.