Former prime minister Scott Morrison breached no laws but “fundamentally undermined” the principles of responsible government by keeping secret his appointment to five departments, the country’s top legal official has found.

In advice released on Tuesday, Solicitor-General Stephen Donaghue found Morrison had been validly appointed to the industry, science, energy and resources portfolio in 2021, but was highly critical of the lack of transparency and recommended the government fix the “deficient” disclosure practices.

Speaking after the release of the advice, Albanese condemned Morrison’s conduct and called on him to issue a public apology. He said the government would launch a further inquiry into the matter, which would be led by a legal expert.

“Scott Morrison owes the Australian people an apology for undermining our parliamentary democracy system of government that we have, something that can’t be taken for granted,” Albanese said.

“It’s one thing to see this as an issue between him and Josh Frydenberg or other individuals, he misses the point here completely. This is about the Australian people. That’s who, at the end of the day, we are accountable for,” he said.

Donaghue’s advice focused on the one department where Morrison exercised powers as the resources minister to block a controversial gas exploration project. He found the appointment was “valid” as the governor-general, acting on the advice of the prime minister, has power under section 64 of the constitution to appoint an existing minister to administer an additional department.

“The governor-general has no discretion to refuse to accept the prime minister’s advice in relation to such an appointment,” Donaghue said.

He said there was no “constitutional or legislative requirement” for the appointment to be notified publicly, but Morrison’s failure to alert ministers, the parliament, or the public was “inconsistent” with the conventions of responsible government under the Constitution.

“The end result is that, to the extent that the public and the parliament are not informed of appointments that have been made under s 64 of the constitution, the principles of responsible government are fundamentally undermined.”

Albanese steered clear of criticising Governor-General David Hurley when asked about his role in appointing Morrison to the departments and whether it was feasible he did not know they were being kept secret.

“The report makes clear ... the governor-general acted upon the advice of the government of the day,” he said.

Albanese also indicated a future inquiry would not examine Hurley’s conduct, including whether he had asked Morrison to make the appointments public, saying his role had already been examined by the solicitor-general. He said that as a matter of protocol, conversations between the prime minister and governor-general were private.

“It’s a matter for the governor-general or for Mr Morrison whether there is any change to that. I’m not privy to that information,” Albanese said.

“But the governor-general has made that point clear in the statements he has made when he also said that there was no reason why he would think it would not be made public. Now, I think there are implications in that statement by the governor-general.”

Donaghue also noted in his advice that he had “not been briefed with any information concerning whether the lack of any notification was the result of a direction from Mr Morrison, or for some other reason”.

Albanese said the cabinet had agreed earlier on Tuesday that the forthcoming inquiry would be led by “an eminent person with a legal background to consider all of the implications”.

Shadow attorney-general Julian Leeser said the opposition would “work with the government on any reasonable proposals to provide clarity to processes and improve transparency in ministerial appointments.”

As a matter of immediacy, Albanese said he had directed the Department of Prime Minister and Cabinet and the Office of the Official Secretary to the Governor-General to adopt a practice of publishing future appointments of ministers to administer departments in the Commonwealth Gazette.

He indicated the government would legislate for this practice to be put into law, in line with a recommendation by the solicitor-general.

“I think one of the things we will need to consider is any future legislative changes to make sure that that is enshrined. To make sure that it is not dependent upon the goodwill of the government of the day,” he said.

The new federal government has officially called a royal commission into the former government's unlawful debt recovery scheme known as "Robodebt".

Prime Minister Anthony Albanese has unveiled the terms of reference and the commissioner who will oversee the inquiry.

Former Queensland Supreme Court Justice Catherine Holmes will lead the commission, with the final report due by April 18, 2023.

The 2015 Robodebt program used an algorithm to work out whether Centrelink recipients had been overpaid, but unlawfully claimed almost $2 billion in payments from 433,000 people.

A total of $751 million was wrongly recovered from 381,000 people.

A $1.8 billion settlement was ordered last year for people who were wrongly pursued and government ministers were lambasted by Federal Court Justice Bernard Murphy over the "massive failure".

Election commitment

Labor committed to establishing the robodebt royal commission at the federal election.

Prime Minister Anthony Albanese has labelled the scheme a "human tragedy".

"The royal commission will examine the establishment of the scheme, who was responsible for it and why it was necessary, how concerns were handled, how the scheme affected individuals and the financial costs to government, and measures to prevent this ever happening again," he said.

"People lost their lives [and] every single member of parliament can tell stories like this."

Social Services Minister Amanda Rishworth said there were questions about why there was no action when complaints were raised.

"We know that as late back as 2016 there were members of public flagging concerns that these debts weren't right," she said.

"These were real flags the government should have listened to."

Government Services Minister Bill Shorten said Australians had never heard how the scheme could be conceived.

"The [former] government has never satisfactorily explained how this monster scheme got away from the system and got a life of its own," he said.

Scott Morrison, who was social services minister when the scheme was established, has said the problem was dealt with by his government when it was scrapped in 2020.

Labor said there were still questions over who held responsibility for the failed scheme and how much they knew.

The federal government said the full toll of the scheme had not been accounted for, including numerous claims of suicides linked to the unlawful program.

Opposition Leader Peter Dutton questioned the motivation behind the inquiry.

"It's nothing more than a political 'get square with Scott Morrison'," he said.

"[They're] looking in the rear vision mirror rather than in front.

"He should be concentrating on families and less on how he can get square."

'A long time coming': class action plaintiffs celebrate announcement

Felicity de Somerville was a plaintiff in the Robodebt class action after she had $11,500 withdrawn from her account to service a debt.

Ms de Somerville, who had the money refunded but did not have her debt wiped, said she was elated by the announcement.

"It is an amazing step forward for our country," she said.

"The Australian public want to know how did this happen.

"Why did they stop thinking about people and start thinking about money.

"You're sitting on that debt for a long time which then flows into your relationship, the other decisions you make financially and personally."

Ms de Somerville said the royal commission would help restore her trust in the system.

"If I ever became unemployed I would not be accessing Centrelink and I'd rather live in my car," she said.

"The royal commission is going to lead to a real change in our human services sector."