Rocky Racoon said:
Chif in '49, of course. He was one of the most decent men to ever serve as Prime Minister of Australia and one whom oversaw profound change (ah yes, when Laborites fought for what they believed in no matter the political costs). Such a scenario would have some rather fascinating ramifications, not only politically (no split in 1954 among other things) but also economically, that's if the High Court deemed his government's attempts to nationalise the banks legal in 1947. And saying this, I don't even consider myself to be a Laborite.
I don't think getting the HCoA to allow the '47 banking nationalisation is enough--the privy council didn't reverse OTL's decision, so I'm inclined to believe there's a more than better chance they would overturn a ruling favourable to the Commonwealth (not than I'm an expert on how the law lords used to interpret the Oz constitution when they were the final court of review, but I'm certain the banks would absolutely, positively take the issue to London, fighting it tooth and nail).
The simplest High Court decision that would stop Chifley from attempting a takeover of retail banking would be if the justices hadn't ruled in favour of the City of Melbourne in the original case brought against the '45 bank laws. It was that reversal that prompted Chifley to issue an ultimatum to the banks, which they then rejected, causing him to go for crash-or-crash-through in the '47 to '49 period of his government.
No bank nationalistion scandal means a much closer election in '49. Add in a decision to postpone the re-introduction of petrol rationing (or at least neutralise the political risk of that decision) and I think Labor falls over the line, much like the Coalition would in close elections in '54, '61, and '69.
(The assault against the banks was uncharacteristic of Chifley, IMHO. F'rinstance, the minister who worked closest with him on the economy, John Dedman, had been convinced that only himself and Eddie Ward wanted to implement a socialist policy RE the finance sector; in the event he was surprised when the PM was the one to propose the move. Since '49 it's been fashionable for historians to analyse Chifley's decision in reference to his grandparents losing their farm during the depression of the '90s, or of Chif's own harsh critique of the banks' behaviour during the Great Depression.
But that back story ignores the fact that he had faith in the original postwar banking regulations. If those laws had never come under attack he wouldn't have felt compelled to confront the big end of town head on.
Otherwise, the forties federal Labor government isn't very socialist. But they were more interventionist than Menzies would be.)
I agree that the fifties split can't happen if Labor is in power for at least an extra term from 1949.