The Japanese government endorsed on Friday a bill to introduce firmer antismoking measures that include an indoor smoking ban for restaurants and a fine for those who violate the rules, hoping to implement the steps by the 2020 Tokyo Olympics.

Japan is among countries rated poorly over its tobacco control policies by the World Health Organization and the government is eager to impose tougher measures to counter passive smoking through the passage of the bill during the ongoing regular Diet session.

It is the first time the country is introducing antismoking measures that carry penalties.

But the content of the bill remains controversial as the government has largely relaxed the requirements for exemptions on an indoor smoking ban at eateries amid opposition from the ruling Liberal Democratic Party, whose members have strong ties to the tobacco and restaurant industries.

According to the bill to revise the Health Promotion Law, smoking would be totally banned inside the buildings of hospitals, schools and government offices. At those premises, outdoor smoking would only be possible in designated areas.

At restaurants, hotels and workplaces, indoor smoking would be banned "in principle" except in special rooms set up for exclusive use by smokers where no food or drink will be served. At hotels, individuals would be allowed to smoke in their own rooms.

Eateries to be exempted from the indoor smoking ban would be facilities with customer seating areas of up to 100 square meters and capital of up to 50 million yen ($468,000). They would not have to establish separate smoking areas if they display a sign in front of the buildings indicating they are a "smoking space."

The ministry had originally planned to exempt bars with a floor space of up to 30 square meters, but ended up expanding the scope of exceptions to win the support of the ruling party.

The compromise plan has triggered criticism from lawmakers seeking tougher measures and a heated debate may take place inside the Diet following the submission of the bill.

As a result of the backpedaling, an estimate shows that customers at some 55 percent of all restaurants and bars can carry on lighting up without going to a separate smoking room, raising questions about the smoking ban's effectiveness.

Under the bill, people who smoke in violation of the rule would be fined up to 300,000 yen and facility managers who fail to take proper measures including removing ashtrays can face a penalty of up to 500,000 yen.

The use of heat-not-burn tobacco products is also regulated in the bill.

About 15,000 people are estimated to die in the country every year from passive smoking, and a government survey in 2016 showed that some 40 percent of nonsmokers said they have inhaled smoke from others at eateries.