Former prime minister Malcolm Turnbull says he is "astonished" the Governor-General was willing to go along with Scott Morrison's secretive appointment to multiple portfolios within his own cabinet.
Mr Turnbull blasted his successor and former treasurer for taking on the ministerial roles — including in health, finance and resources — without telling the public or, in some cases, the existing ministers.
"This is sinister stuff. This is secret government," he told 7.30.
"This is one of the most appalling things I have ever heard in our federal government. I mean, the idea that a Prime Minister would be sworn in to other ministries secretly is incredible."
Mr Turnbull said he was "astonished" that the Department of Prime Minister and Cabinet had "gone along" with the appointments, which have now come to light through media reports sourced from court documents.
But he said he was even "more astonished" that the Governor-General, David Hurley, was involved.
Mr Morrison's secret ministries were completely different to more routine arrangements where ministers act in different roles while a colleague is unwell or on leave, according to Mr Turnbull, because those arrangements were made public.
"We, the people, are entitled to know who is governing our country. We need to know who is the minister for this, who is the minister for that. If, in fact, these things are all being done secretly, that's not a democracy."
In a statement this afternoon, a spokesperson for the Governor-General said Mr Morrison was appointed to his extra portfolios under "normal process", consistent with the constitution.
"Questions around appointments of this nature are a matter for the government of the day and the Department of the Prime Minister and Cabinet," the statement read.
"Similarly, the decision whether to publicise appointments to administer additional portfolios is a matter for the government of the day."
7.30 asked the Department of Prime Minister and Cabinet if it had prepared papers or a briefing about the appointments for the Executive Council, which is the body that advises the Governor-General.
The department did not directly respond, instead simply confirming Prime Minister Anthony Albanese had asked it to "provide advice on this matter".
Turnbull supports Voice, regrets 'third chamber' characterisation
The former Liberal prime minister Mr Turnbull has also thrown his weight behind the upcoming 'yes' campaign for a referendum to create an Indigenous body to advise the parliament, enshrined in the constitution.
Mr Turnbull said he regretted describing the proposal as a "third chamber" of parliament while he was prime minister.
"I do regret using that term, because it was misunderstood," Mr Turnbull said.
"I never intended to convey the idea that it would be a third chamber like the Senate is a second chamber."
Mr Turnbull said he still had "reservations" about the model, and stressed that it would be a "big change" to power dynamics in Indigenous affairs, not mere symbolism.
"I believe our parliamentary democracy can handle it," he said.
He said a 'yes' campaign would have been doomed while he was leader, but the momentum behind the idea now meant it was a "winnable" proposition.
"I say that with great trepidation. There's a lot of work to be done," he said.