Despite the air-punching of nanny state lobbyist Simon Chapman that the debate over the legality of plain packaging is over, previous rejections of the idea by the Canadian, New Zealand and British governments suggest otherwise.

Chapman’s claim that Monash University’s Mark Davison delivered a “consummate demolition job of the specious huff and puff” of the legal and policy arguments against plain packaging is a demonstration of Chapman not being able to clear from his eyes the sunny glare piercing his university ivory tower windows.

In university public health departments it may not appear common for different people to have different legal perspectives, especially on such a controversial issue, but I assure Chapman that they are pretty common. That’s why we have courts to resolve them.

Both Davison’s and my presentations were nothing more than presentations of legal arguments from different perspectives. Though I’ll concede I was more interested in discussing the issues, than proving a point.

But commentators need to be careful about arguing the legal specifics since the Rudd government hasn’t released its plain packaging legislation. At the moment detailed commentary can only relate to the deficient and now defunct plain packaging legislation proposed by Senator Fielding.

And, despite how it may appear, there is agreement between the differing legal perspectives. For example, the current packaging and labelling requirements and encumbrances on the display of trademarks are consistent with Australia’s international trademark obligations. And no one is arguing that the World Trade Organisation’s Agreement on the Trade Related Aspects of Intellectual Property Rights (TRIPS) doesn’t provide the owner of a trademark the right to use it.

But there is also disagreement. For example there remains an argument that plain packaging may breach Article XX of TRIPS because it unjustifiably encumbers a trademarks capacity to distinguish goods and services from each other. And when you think about that is the precise intention of plain packaging. Also there remains an argument that the public health exception under the principles section (article VIII) of TRIPS doesn’t provide blanket protection because it requires consistency with the aforementioned Article XX, and that broad interpretations of the term “public health” is limited to discussion about medicines.

And several individuals and groups are raising these concerns such as the International Trademarks Association. And then there’s the Institute of Patent and Trademark Attorneys who also raise concerns.

There are plenty of other examples of the to-ing and fro-ing of different legal interpretations, but no one can say with absolute certainty what the courts will decide. As the government keeps pointing out, Australia would be the first in the world to legislate for plain packaging which, Mr Chapman, inherently brings with it legitimate debate about its legality.

Tim Wilson is director of the IP and Free Trade Unit at the Institute of Public Affairs.