At the end of every advert, where we currently have “Authorised by”, add “This advert was paid for by the Australian taxpayer”. Then let democracy take its course.
The neat thing is that if ads were genuinely helpful and informative, tazpayer-viewers wouldn’t mind.
A requirement of this kind could be inserted by legislation, and it would be a brave government that subsequently removed it. Of course, it would only happen if it could be done in the first few days after a change of government, when the habits of power had not yet grown familiar.