"The movement is using legal actions to cushion the expected opposition from the public [if it is successful]," Chamlong said.

"The Council of State was so quick to accept the matter for consideration," he added, speaking on the council's decision to consider a complaint filed against the ban through Prime Minister Surayud Chulanont.

"I want to warn those who are behind the movement ... you are causing huge damage to society," he said.

Chamlong said the ban on alcohol advertising was a remarkable effort to create a clean environment for youngsters and had been proposed during the past government's tenure but had been repeatedly rejected by those who had "higher power".

"If the ban, which has high public support, is put on hold by this government, I can't help worrying about the future of it as well as of the nation," said Chamlong, who jointly led street campaigns against ousted Prime Minister Thaksin Shinawatra earlier in the year.

Dr Narong Sahametapat, deputy director general of the Public Health Ministry's Disease Control Department, said yesterday that the Council of State had questioned the ministry about the complaint against the ban, which presumably was filed by a group of alcohol companies.

He said the council questioned if such a ban was legitimate, to which the ministry replied that it had already been considered by a panel of public law experts.

"We're pretty sure it's legitimate," Dr Narong said.

In response to the legal argument expected to be used against the ban, which claims that the ban is illegitimate because there are already laws that govern such matters, Thammasat University lecturer and member of the Assets Examination Committee, Assistant Professor Banjerd Singkaneti, said similar exceptions had already been made to regulate cigarettes and motorbikes. It was a matter of legal interpretation, he said, which in the case of cigarettes and motorbikes had to consider the public interest.

"If it's ruled that the ban on alcohol is not lawful, they will have to reconsider similar directives that have existed for more than a decade," he said.

Dr Pirote Ningsanonda, a member of the council's committee that is considering the matter, confirmed the council would discuss the ban and opposition to it on Thursday.

An informed source said the council's committee might consider allowing some alcohol advertising, as requested by alcohol companies.

Meanwhile, Dr Suphan Srithamma, a spokesman for the Public Health Ministry, said the ministry would proceed with the ban and had called a meeting of chief health officers from all provinces next Monday to explain the ban before it comes into effect.