Persistent discourse about what some critics see as the failed effectiveness of plain packaging does not detract from proven, consistent facts from reliable sources.

In the 22 months after plain packaging was introduced in December 2012, tobacco and cigarette spending fell by 7.3 per cent, according to ABS statistics.

Until we see evidence proving otherwise, it is crucial we question counterarguments. All too often, these arguments are influenced by Big Tobacco’s attempts to erode the very legislation created to reduce death and disease caused by smoking.

Yes, tobacco excise has played a role in smoking rates falling. But why would we criticise this when it has been part of the united solution? It’s a simple notion — fewer people smoking cigarettes means fewer people dying.

But with smoking rates continuing to fall, who would want to attack life-saving legislation?

The answer is Big Tobacco. So it comes as no surprise the Institute of Public Affairs, which receives Big Tobacco funding, continues to use unreliable data in its arguments to discredit plain packaging.

To say plain packaging has resulted in increased illicit tobacco use is problematic.

Health groups have questioned the validity of the internet surveys used in industry studies as part of KPMG’s report on illicit tobacco. These same surveys have been used to form these claims.

Cancer Council Victoria has shown that data from sources independent of the tobacco industry indicate there are relatively low and stable levels of illegal tobacco use in Australia.

Furthermore, their critique offers alternative estimates on illegal tobacco use in Australia and refers to results from the 2013 National Drug and Alcohol Survey.

These suggest a decline since 2007 in the percentage of smokers who are aware of unbranded tobacco, who have ever smoked it and who currently use it.

Yet time and time again we see Big Tobacco quick to laud dubious evidence in its arguments that plain packaging has failed.

Plain packaging laws are absolutely necessary. They play a pivotal role as part of a raft of measures designed to help smokers quit.

Importantly they prevent people from taking up smoking and, as a result, less people die and suffer from smoking-related disease.

The opinion piece on Wednesday by Simon Breheny, Legal Rights Project director at the Institute of Public Affairs, is just the latest example of a Big Tobacco smoke-and-mirror job.

Will it be Big Tobacco’s last attempt at peddling their message that plain packaging does not work? Certainly not.

Will their attempts undermine the fact that preventing people from smoking saves lives? Never.

Prof Nicholas Talley is president of the Royal Australasian College of Physicians