A royal commission into banks is back on the agenda in the dying days of the election campaign, after whistleblower Jeff Morris asked about the issue on national television.

On Monday night's Q&A, the last before the election on Saturday, Mr Morris – a former financial advisor who exposed unethical practices at the Commonwealth Bank – asked finance minister Mathias Cormann why nothing had been done to address banking scandals.

"Mr Cormann, eight years ago I became the whistleblower in the Commonwealth Bank financial planning scandal," Mr Morris began.