I understand all the internal Aussie politics...but there is one thing the PM could do...
and that is speak loudly and clearly that the states are engaging in Pfascism which is a clear violation of the Nuremberg Codes.
He should remind them that at some future date they may be subject to international sanctions, up to and including public execution, for crimes against humanity—for ill effects and deaths from the vaxxes taken under duress.
Then he has gone on record and given them a warning.
What happens after that is their call.
and that is speak loudly and clearly that the states are engaging in Pfascism which is a clear violation of the Nuremberg Codes.
First of all, no, the state governments are not clearly violating the Nuremberg Code. It's an arguable position, but it's not a clear one. For it to be a clear violation, vaccination would have been mandated by law for all people regardless of circumstances - and even there it's not 100% clear unless the vaccine is still considered experimental (and under Australian standards, AstraZeneca and Pfizer are no longer considered to be experimental - Moderna is approved but still considered experimental - no other vaccines have been approved at all yet - that's a decision by an independent body, not government). Mandates for people with specific jobs (which is what we have here) or as a condition to avoid quarantine rules don't clearly qualify.
Secondly, even if they were, it's irrelevant. The Nuremberg Code has no force in Australian law. Australia does not automatically apply international declarations to our laws (Thank Goodness, because some of those international declarations aren't good).
Thirdly, all it would do is more clearly show that the Prime Minister is powerless and that would likely embolden the state governments that are engaged in bad behaviour. If they are going to be accused of such serious violations for just mandating vaccination to work in high risk situations, why wouldn't they just mandate vaccines for everybody? It would make it more likely they'd do that.
Fourthly - and I know it's hard to see from outside (at times, it hard to see from inside) the Prime Minister is actually making progress with negotiations. We now have in principle agreement with the idea that the country should open up even if COVID numbers can't be brought down to zero. That's a huge concession by the states, especially by Victoria and was only achieved by negotiation. Antagonising them doesn't do any good. Negotiating does.