Walk in to a local shop or supermarket tomorrow and a mainstay of shelves will be missing forever.

As of May 20, it’s illegal for retailers to sell branded cigarette packs. This follows a landmark ruling from MPs back in March 2015 that all tobacco products should be sold in drab, standardised packaging that’s littered with large health warnings.

Manufacture of branded packs halted in May last year, and tomorrow retailers will have to stop selling their branded stock. This marks the final nail in the coffin of tobacco advertising.

How cigarette packs are changing

In the UK, the shift to standardised packaging follows a long line of policies to tackle tobacco. In the 1950s, we part-funded the first study to link tobacco with cancer. Since then, governments in the UK have shown their commitment to eliminating deaths caused by tobacco.

There have been successful tax increases to make tobacco less affordable, many mass media campaigns convincing smokers to quit, and a ban on smoking in public places.

As a result of all these initiatives, smoking rates have dropped from more than 50% in the 70s to an all-time low today of around 17% in the UK.

Tobacco control policy

That’s a huge success. In fact, the UK was recently voted the best European country for effective tobacco control policies by the Tobacco Control Scale. And in terms of advertising, the UK has led the way. In 1965, the British government banned TV advertising of cigarettes. This was followed a decade later by a ban on sports sponsorship, and in 2015 point of sale displays in shops.

Now, standardised packaging is added to this list.

So, with branding gone from packs and that final piece of advertising removed, the big question now is: what effect will standard packs have?

Do standard packs work?

A couple of weeks ago, the Cochrane Collaboration, which reviews large collections of healthcare evidence, published a study offering an early glimpse of the impact standard packs could have. The study, led by researchers from London and Oxford, found that based on the available evidence from Australia, who swapped the packs in 2012, standardised packaging may reduce smoking rates.

At the moment that evidence is limited because the new packs simply haven’t been around long enough for us to see the full impact. But this is a positive early indication.

In fact, the researchers estimate that smoking rates in the UK could go down by 0.5% by May 2018, which – based on our calculations – could mean 257,000 fewer cigarette smokers as a result of standardised packs.

Tracking this impact will be an ongoing topic for researchers. And we’re funding several studies to evaluate the impact of standard packs in the UK.

Among other things, the studies will measure what young people and adults think about packs, including how they perceive the contents. These studies will also look at the impact of plain packs on the numbers of people smoking, new people starting, and the numbers trying to stop. They will also look at changes in the price and variation in price between tobacco brands, changes in consumer behaviour, impact on tobacco industry profitability and tobacco industry tactics to try and dodge the legislation.

It will take years to see the full influence of standard packs, but it’s crucial to evaluate a policy like this every step of the way. The early evidence is showing that they are having an impact in Australia. And the tobacco industry knows this.

Why is it important to evaluate?

Unsurprisingly, the tobacco industry hasn’t been a fan of the makeover to packs.

Several lawsuits have been filed against countries, including the UK, who have decided to introduce standard packs. In these legal challenges the industry claims, among other things, that packs will increase illicit trade because they can be easily replicated (there is no evidence to support this claim), and that not allowing a company to show its brand on packs is an infringement on its trademark. They also claim the legislation breaches human rights.

In a court case in the UK, a lawyer for Japan Tobacco even argued the tobacco industry should receive a multi-billion dollar compensation for lost profits, comparing the situation to the compensation given to slave owners when slavery was abolished.

The tobacco industry hasn’t won one of these legal cases. So why keep trying?

The lawsuits are yet another tactic employed by the industry to cast doubt over the policy, even though there’s no evidence to back up the claims being made. This means they are trying to dissuade other countries from introducing plain packs by threatening costly and time consuming legal challenges.

And that’s why it’s so important for countries like the UK to measure the impact of standardised packs.

If the policy is effective at reducing smoking rates and demoralising the tobacco industry, then this needs to be proved. And if it is proved, that information needs to be shared with the world. We need to lead the way for other countries to implement this law, especially in the case of those who don’t have the resources to fight these inevitable legal challenges.

The good news is that public health is winning this battle. Two weeks ago, it was reported that the World Trade Organisation has decided to back Australia’s laws on plain packs, deciding that packs don’t unjustifiably infringe upon trademark rights.

There’s also a growing list of countries that have decided to swap branded packs for standard ones. France has now completely switched, and New Zealand, Norway, Hungary, Sweden, Finland, Turkey, Bulgaria and Canada are following on behind.

We still have a long way to go. But we believe that building on evidence we have, we will help strengthen the case to eliminate tobacco advertising globally, for good.

Alyssa Best is a policy advisor at Cancer Research UK