Well something doesn't gel with Parliament's website.
"The approval of the Governor-General to the composition of the Ministry, the creation of departments, the allocation of portfolios and any ministerial and departmental change is notified publicly[73]and announced in the House.[74]The principal areas of departmental responsibility and enactments administered by the respective Ministers are notified publicly by order of the Governor-General.[75]Temporary ministerial arrangements may be made by the Prime Minister without reference to the Governor-General."