Scott Morrison's decision to secretly appoint himself to five different portfolios while prime minister is a "black mark" on his behaviour, according to Nine's political editor.
Morrison fronted the media on Wednesday afternoon in a defiant press conference where he defended his actions, saying they were necessary steps during extraordinary times.
However, Nine political editor Chris Uhlmann said the former PM's reasoning didn't stack up.
READ MORE: Morrison says 'extraordinary times' justified secret ministries
"It is a bit hard to follow some of the logic, I have to say, that he needed these emergency powers and proof that he had confidence in his ministers was that he never used (the powers)," Uhlmann said.
"If he had confidence in his ministers, then you wouldn't think that he needed (the powers) in the first place."
Uhlmann went on to say Morrison had trashed the conventions of the prime ministership.
"A cloud hangs over the way he acted," he said.
READ MORE: Morrison says he only planned to use powers in an emergency after secret swearing into ministries
"He rightly says again it was in extraordinary times. And no Prime Minister since the Second World War has faced times like this. An enormous number of things that were done at a state and territory and federal level now do need a lot of examination.
"We need to learn the lessons of the past. I think one of the lessons we are learning at the moment… this is a black mark over the way that he behaved when he was prime minister.
"Although it might have been legal, convention is important, and this was a trashing of that convention."
READ MORE: Explained: The Morrison secret portfolio story
Uhlmann said Morrison's move to the health portfolio was to put checks and balances on the Biosecurity Act – a "very bad piece of law" – at the start of the pandemic, but that the other ministries had less and less to do with COVID-19.
"Then he goes further, into home affairs. Goes further, into treasury, not telling any of the ministers involved in that and he says because he didn't want to undermine their confidence," he said.
"The only time he used these powers were when he was wanting to knock off a resources project, which had nothing to do with the pandemic."