ScoMo said he did not dispute claims he took joint power over a fourth ministry, the social services portfolio, in June 2021, during the COVID-19 pandemic.

"I don't recall that ... I don't dispute that and my answer for all that is the same, we were dealing with an incredible amount of discretion and money being paid," Mr Morrison told Sydney radio station 2GB.

"They were unprecedented times and as a result they were very unconventional times.

"Fortunately, none of these [appointments] in the case of the finance and the health portfolio were ever required to be used."

How could Morrison be sworn in to several portfolios?

There is still much about these reports that remains unclear — but, in any case, it is inappropriate for a government to act with secrecy on such matters, writes Anne Twomey.

Mr Morrison apologised to his former finance minister Mathias Cormann for keeping the move secret from him, saying he assumed the decision had been passed on by his office.

He said he could not recall whether he had assumed power over any other portfolios and that he was pursuing that matter, but said there were a number of others that had been considered.

The former prime minister said he appointed himself as a backup to other ministers at the height of the COVID-19 pandemic as a "safeguard and a redundancy".

"They are very complex, detailed issues in governance … I put in place a set of arrangements that ensured all decisions could be made instantaneously. That is the real-time crisis we were dealing with."

Morrison used secret powers in decision unrelated to pandemic:

But Mr Morrison also admitted that he took control of the resources portfolio in 2021 to overrule then-minister Keith Pitt to block a petroleum exploration licence off the NSW Central Coast.

He acknowledged that decision had nothing to do with the pandemic.

"That was a very different issue … it was one I sought to be the decision-maker on that issue because of the importance of that issue," Mr Morrison said.

"This is a power a minister has that is not overseen by cabinet … the minister makes their own decision and the prime minister can't direct the minister."

"I always respected Keith's role as the decision-maker, and if I wanted to be the decision-maker, I had to take the steps that I took."

He said the ministers were running their portfolios without interference, except in the single instance with the petroleum licence.

When Mr Morrison was challenged on why he kept the power grabs secret from his own cabinet ministry, he argued that they were decisions between himself and the relevant ministers and not a matter for cabinet.

He said it was an oversight that in Mr Cormann's case he did not discuss that decision.

Liberal Senate leader Simon Birmingham said he found Mr Morrison's decision to override the then-resources minister "Curious, troubling and worthy of some explanation".

"Only the former prime minister, I guess, can do that in terms of the processes he went through," Senator Birmingham said.

Senator Birmingham said he recalled a discussion about Mr Morrison having himself "sworn into" the health portfolio.

But he said he was not aware of whether the former PM had also been acting in the finance portfolio after Senator Birmingham took it over from Mr Cormann.

Prime Minister Anthony Albanese has asked his department to seek legal advice from the solicitor-general over Mr Morrison's decisions.

Original Story By | Jake Evans