Their is nothing to stop a PM from holding ministerial portfolios from my understanding. However, these positions are usually appointed by the GG on advice of the PM, Parliament is informed and it is gazetted.
There is an Acts interpretation decision that allows for an acting Minister to be appointed without GG approval for a "temporary" purpose. It seems to have been intended for when a Minister is on leave, sick or absent. To use it otherwise would appear an abuse of power and attempt to circumvent the GG and the need to disclose the appointment to the Parliament and public. This, in a reasonable view, could not be seen as a proper use of such a provision, as it lends it self to abuse and circumventing the proper democratic processes and cabinet system. Stranger things have happened though.
My personal view is the secrecy is of the utmost concern, as certain decisions are based on who holds the decision making power. For instance, the entities involved in PEP11 and their shareholders may have made other decisions had they known Scomo was a Minister responsible for the final decision. Secretly the PM has grabbed more power, without the oversight of The Parliament and, more importantly, the knowledge of the people.
I am a right of center conservative voter who lost respect for Morrison early on. I am no fan of the current PM as well. Saying that, Morrison single handily barstardised the democratic process, showed contempt for the Constitution and its conventions and should resign from the place he disgraced. Maybe it ends up being a slimey legal trick that worked, but it is totally against the spirit of an open and democratic society.
