ZURICH (NYTIMES) - The images are jarring to visitors: happy, glamorous couples smoking together in a cafe, packs of cigarettes opened invitingly, rugged Western landscapes that evoke the Marlboro Man.

While many countries have long banned cigarette advertising, it has lived on in Switzerland, where loose regulations on the sale and marketing of tobacco products make the country an outlier in much of the Western world. The ads adorn billboards on city streets, are shown in cinemas, and are ubiquitous at sports and cultural events like Montreux's famed jazz festival.

But this weekend, much of that may start to fade away as Swiss voters decide whether to place restrictions on tobacco ads that would effectively ban them in public spaces.

The initiative, which is expected to pass in a referendum, according to polls conducted by Swiss media outlets, has been endorsed by health advocates who cite findings by bodies like the World Health Organisation that the ads encourage young people to smoke and make it harder for smokers to quit.

“We want to protect young people and ensure tobacco prevention efforts are not undermined through advertising,” said Hans Stöckli, who is president of the committee behind the initiative.

The initiative has unsurprisingly been opposed by the tobacco industry, but also by the government, which has maintained unfashionably friendly relationships with tobacco companies that have set up regional and even global headquarters in Switzerland. A majority of members of Parliament have also come out against it. Many of them say jobs will be lost if the referendum passes, since cigarettes rank with chocolate and cheese as some of the country's leading exports.

If voters approve the initiative, advertising for tobacco products, including e-cigarettes, would no longer be allowed in places or on websites that are accessible to those under 18.

Even though it would not be a blanket ban, it would nonetheless represent a significant change. Switzerland is one of the few places in Europe that has not introduced a nationwide ban on the sale of tobacco-related products to minors. Although some parts of the country ban sales to children under the ages of 18 or 16, others have no minimum age, and in many places young people can be seen puffing away in public.

Switzerland has been unable to ratify the WHO’s Framework Convention on Tobacco Control, despite signing it in 2004, because of its insufficient restrictions on sponsorship and advertising. The United States has also not ratified the convention.

Stöckli said that even if voters approve the new legislation, Switzerland would still lag behind other countries on regulating tobacco. He said advocates had focused on protecting children and young people, instead of a blanket ban, to improve the chances of the law passing.

“It was a compromise,” he said, adding that he would keep pushing for tighter regulations and higher taxes on tobacco products, including e-cigarettes, which contain nicotine extracted from tobacco.

Switzerland has long courted multinational tobacco companies. Philip Morris and Japan Tobacco International have their international headquarters in the country, and British American Tobacco also has a strong presence. The sector employs about 4,500 people in Switzerland, according to the government, including in the production of high-tar cigarettes that are illegal to produce or sell in the European Union.

Sunday's referendum came out of a 2015 proposal by the Federal Council, Switzerland’s executive branch, for a Tobacco Products Act that would ban the sale of tobacco to minors nationwide and restrict advertising. Parliament eventually approved an amended bill that would leave most advertising intact.

In response to the weakening of the legislation, a group made up of more than 40 health organisations launched an initiative to make it tougher, and assembled the necessary signatures needed to put it to the voters.

If Swiss voters reject the initiative on Sunday, the amended bill will come into effect without the broad restrictions on ads.

The initiative also includes restrictions on offering discounted or free tobacco products and on industry sponsorship of events that are accessible to minors.

Despite strong support from civil society organisations, the initiative has faced a lot of opposition from politicians in Switzerland.

Mike Egger, a member of the Swiss People’s Party and co-president of a group formed to encourage people to reject the initiative, said the proposed advertising restrictions were against Switzerland’s liberal values.

“The initiative calls for a ban on advertising a legal product,” he said.

Egger said that the harmful effects of smoking were well known in Switzerland, and that tobacco packaging already included warnings. Cigarette packs carry both written warnings and the gruesome pictures of diseased body parts that have become common in many countries.

“I trust that citizens can themselves decide whether they want to consume tobacco products or not, and there is no need for a superstate that regulates the sector more strongly,” he said.

Anti-smoking advocates have also accused the Federal Council of cosying up to the tobacco industry. They pointed to a statement in which the council said that the initiative was welcome from a public health perspective, but that it “had to weigh the public health interests against those of the economy” and supported limiting “advertising to an extent that is acceptable to the tobacco industry”. In the statement, the council acknowledged that almost half of smokers started the habit as a minor, and that tobacco use was responsible for around 15 per cent of the nation’s deaths.

Pascal Diethelm, an anti-tobacco campaigner and a proponent of the initiative, said the declaration by the Federal Council was shocking.

“This is smoking-gun proof that the government has put the tobacco control policy, which is a public health policy, under the tutelage of the tobacco industry,” he said.“I don’t see any other country in the world which has done that,” said Diethelm, pointing to the council’s rejection of the initiative despite its acknowledgment that an advertising ban would not only benefit children, but also adults, and reduce the high costs associated with smoking.

Martin Kuonen, director of Swiss Cigarette, an association that includes Philip Morris, Japan Tobacco and British American Tobacco, said the tobacco industry was “fully in favour of the protection of minors” and agreed with the idea of setting a minimum age for buying its products.

But Kuonen said the tougher legislation proposed by the initiative went too far. “It is a de facto advertising ban,” he said, because children can potentially be exposed to advertisements anywhere. He said the industry strongly opposed this, as “adults will indirectly also be affected”.

Kuonen said that if the public votes in favour of the initiative, the tobacco companies “will have to think twice about whether they want to continue investing in Switzerland.” But Diethelm said he doubted the industry would seriously consider uprooting and moving elsewhere.

“Where should they go?” he said. “I don’t see any decently governed country that would want them.”