The latest comes after revelations Mr Morrison secretly took control of five additional portfolios, without the knowledge of the vast majority of his party and the public.

He held five secret portfolios - finance, health, resources and energy, treasury, and home affairs - during the pandemic and did not relinquish authority before the May election.

"He [Scott Morrison] told us he was a bulldozer and his Coalition colleagues just shrugged their shoulders and cheered him on, not in one election but in two elections," Prime Minister Anthony Albanese said.

"Turns out, he was the world's first stealth bulldozer. Operating in secret, keeping the operations of the government from the Australian people themselves."

Mr Albanese fronted reporters in Parliament House after further briefings from his department head on the explosive revelations.

He said Mr Morrison engaged in "unprecedented trashing" of democracy by covertly assuming power in a handful of departments between March 2020 and May 2021.

In a thousand-word open letter on Facebook on Tuesday, Mr Morrison insisted the COVID-19 pandemic necessitated "extraordinary measures to respond", but claimed he did not remember being given authority over the treasury and home affairs portfolios until recently.

Mr Morrison claimed he only used his extraordinary powers once - to scuttle a controversial NSW gas project - and that he never attempted to interfere with ministers' "conduct in their portfolio".

He said there was "no guidebook" in how to handle a crisis like COVID-19, and claimed the measures were necessary to ensure he could exercise a minister's function if they were struck down by COVID-19.

Former home affairs minister Karen Andrews has declared Scott Morrison has blindsided her and is calling on him to resign from Parliament.

However the Opposition Leader, Peter Dutton, has defended his former leader and is calling for people to wait until all the facts of the controversy are known.

The former PM was secretly given control over the Home Affairs Department during an unprecedented ban on travel from India.

The now opposition home affairs spokeswoman doesn't know whether his secret appointment was related to the India travel ban.

The measure, announced on April 27, 2021, prevented flights to Australia from India as the country grappled with a deadly outbreak of the COVID-19 Delta strain.

Mr Albanese said Mr Morrison was covertly given power over the Home Affairs Department on May 6, 2021, nine days before the ban was initially slated to end.

It was the first law in Australian history making it illegal for citizens to return home.

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