Scott Morrison appointed himself to five ministerial portfolios at various times in the past two years, Prime Minister Anthony Albanese says.

The revelations, as advised by the Department of Prime Minister and Cabinet, represent an astonishing escalation of claims that emerged at the weekend that Mr Morrison had secretly taken over the health and finance portfolios in the early days of the COVID pandemic.

Accusing his predecessor of misleading Parliament, Mr Albanese said on Tuesday the full list of clandestine appointments was:

• Department of Health on March 14, 2020
• Department of Finance on March 30, 2020
• Department of Home Affairs on May 6, 2021
• Department of Treasury on May 6, 2021
• Department of Industry, Science, Energy and Resources on April 15, 2021.

“He told us he was a bulldozer  … turns out, he was the world’s first stealth bulldozer,” Mr Albanese said.

“Operating in secret, keeping the operations of the government from the Australian people themselves, and misleading parliament as to who was holding what portfolios and who was responsible.”

Mr Albanese said each appointment was made under section 64 of the Constitution.

“It is completely extraordinary that these appointments were kept secret by the Morrison government. It is completely contradictory, too,” he said.

“For example, the questions that ministers answered on the floor of the House of Representatives and the Senate. You ask questions of ministers who are responsible for a portfolio.”

He said the implications of the secret appointments were still being worked through, and further advice had been sought from the Solicitor-General. It is expected by next Monday.

“We know that there is a legal matter in the issue of resources,” Mr Albanese said.

Mr Morrison apparently declared that his joint role in the resources portfolio only when he told the cabinet minister, Nationals MP Keith Pitt, that Mr Pitt did not have the authority to approve a controversial gas project. Mr Morrison subsequently announced the decision to cancel the project.

Mr Morrison broke his silence on some of the extraordinary appointments on Tuesday, saying it was done as a precaution during the the pandemic.

He defended the secrecy, saying the moves was a safeguard and that he would have made it public had he needed to use the powers involved.

“Sometimes we forget what was happening two years ago and the situation we were dealing with; it was an unconventional time and an unprecedented time,” he told Sydney radio station 2GB on Tuesday.

“[British PM] Boris Johnson almost died one night. We had ministers go down with COVID.”

Mr Morrison called the actions “a two key approach”.

“We had to take some extraordinary measures to put safeguards in place,” he said.

“Fortunately, none of these in the case of the finance and health portfolio were ever required to be used.

“The powers in those portfolios, they weren’t overseen by cabinet. The minister … in both cases had powers that few, if any, ministers in our federation’s history had.”

Mr Morrison said he didn’t recollect other ministries he took on outside health, finance and resources. However, even before Mr Albanese’s announcement, documents had revealed Mr Morrison had been sworn in to oversee aspects of the social services portfolio.

“No, not to my knowledge no,” Mr Morrison said when asked directly if he was sworn into social services.

Mr Morrison was forced to clarify his position minutes later, saying: “I don’t recall that but I mean, as I said, there was some administrative issues done. I don’t dispute that.”

He said everything had been done to ensure the “buck stopped with the prime minister” as he had no legal powers to directly order a minister to take a certain decision.

“If I wished to be the decision maker, then I had to take the steps that I took,” he said of his call to overrule Mr Pitt.

“People know where the buck stops and the buck stops with the prime minister. I sought to be the decision maker on that issue because of its importance.”

Mr Albanese said there were other implications from Mr Morrison’s secretive takeovers – including in home affairs, when a controversial text message was sent on election day about an asylum seeker boat.

Mr Albanese described the message, sent to millions of voters, as a “shocking breach” of government policy and information put out to “try to pervert the result of the election on May 21”.

“This is a sad indictment. Of not just Mr Morrison, but all those Cabinet colleagues of his, who sat back and allowed this to happen. It’s undermined our democracy,” he said.

“It’s an attack on the Westminster system of parliamentary democracy as we know it. And not just Mr Morrison, but others, who were involved in this, need to be held to account in the former Morrison government.”

Mr Albanese said he was not aware that any of the appointments had an end date, or if Mr Morrison had received any extra pay.

Earlier, Mr Albanese declined to directly express his support for the governor-general, who was involved in at least some of the secret swearing-ins.

“The governor-general’s job is to take the advice of the government of the day. I don’t intend to pass judgement,” he said.

A spokesperson for Governor-General David Hurley says he followed processes consistent with the constitution when he appointed Mr Morrison to the additional portfolios.

“It is not uncommon for ministers to be appointed to administer departments other than their portfolio responsibility,” the spokesperson said in a statement.

“These appointments do not require a swearing-in ceremony. The governor-general signs an administrative instrument on the advice of the prime minister.”

-with AAP