From the Alcohol Reform Cabinet paper:
24. The purchase age is currently set at 18 years of age. The Commission recommends that the purchase age be raised from 18 to 20 years with no exceptions.
25. I recommend introducing a split alcohol purchase age of 18 for on-licence sale and supply and 20 for off-licence sale and supply (recommendation 119).
26. I note that alcohol legislation has traditionally been subject to a conscience vote and a decision to vote along party lines is a matter for each caucus. I anticipate that any proposal to amend the alcohol purchase age will continue to be considered by Parliament as a conscience matter and the Alcohol Reform Bill will be drafted in a way that supports this approach.
Age splitting effectively imposes an excise tax on drinkers aged 18-20, only the money goes to the hospitality industry instead of the state. The industry lobbyists are very enthusiastic about an age splitting policy so I’m pretty sure Parliament will find it in their ‘conscience’ to vote in favor of the proposal.