The two major alcohol firms in Thailand are Boonrawd Brewery and the Singapore-listed Thai Beverage.

He questioned if the ban was meant to favour some companies. For example, the regulations forbid advertising containing an alcohol product logo but does not prohibit the advertising of drinking water and soda products that bear the same logo.

"This makes companies with only alcohol products lose advantage to those with both drinking water and alcohol products," he said.

According to the intellectual property law, if an alcohol product and drinking water use the same logo, the logo is treated as the same trademark, he said.

Boonchuay also questioned why the total ban would not cover the advertising of alcohol products during live international broadcasts to Thailand.

"The business community needs fair competition and fair regulations, and we believe that any unfair regulations will soon be cancelled," he said.

He also claimed that the FDA had no authority to introduce regulations to ban alcohol advertising.

Public Health Minister Mongkol Na Songkhla said his ministry would convene a meeting of all provincial public-health chiefs on Monday to brief them about how to enforce the ban.

"We can expect some hiccups in the very beginning because this is a new measure. However, with close monitoring, the measure will be efficiently implemented in the future," he said.

Mongkol said the ban was proposed for public benefit, especially for youths.

He said the ban on alcohol ads could begin with a lenient phase during which offenders would just receive warnings.

"But after a period of time, we will be tough with enforcing the ban and offenders would be bound to face legal action," he said.