Peter Dutton and Linda Reynolds (Images: AAP)

Public servants in the two biggest departments, Defence and Home Affairs, will be hastily preparing ministerial briefs over the next two days on the suspicion that they'll have new bosses to brief any minute now.

Those in the Attorney-General's Department -- far smaller but also important -- will be doing the same, although they've had an acting minister for a while now. There may well be other consequential ministerial changes -- if Linda Reynolds merely gets demoted and not dumped, she'll need briefing in her new role, while the incumbent there will move elsewhere.

Home Affairs and Defence are two of the worst-performing portfolios in the Commonwealth. In the case of Defence, to be fair, many of the problems are not of its own making. The submarine project is a debacle because of the Turnbull government's protectionist decision to build the things here in Australia, adding a huge premium to the cost, the likelihood of significant delays, and ongoing tensions with Naval Group and French politicians who see the whole deal as primarily about jobs in France, not Adelaide.