Lam, the University of Hong Kong's chair of community medicine, made the comment ahead of World No-Tobacco Day today, saying the cost of regulating e-cigarettes will be high. Allowing e-cigarettes will harm youngsters and the public healthcare system, he said.

Lam said the authorities would have to invest a lot of money if they wanted to regulate these new tobacco products, since they may need to set up a new laboratory. "The most cost-effective way is legislating to ban e-cigarettes and heated tobacco products."

In 2019, the government proposed the Smoking (Public Health) (Amendment) Bill, which banned the import and sale of electronic cigarettes. The amendment, introduced to the bills committee, was later shelved.

However, some lawmakers see regulation as the way forward.

Peter Shiu Ka-fai said that 64 countries, including China, had started regulating these products. He also said that authorities should handle e-cigarettes and heated tobacco products separately, as there is insufficient evidence to ban heated tobacco products now.

Lam criticized those who opposed the bill, saying they usually had vested interests. "They are sacrificing public interest and health for the benefit of a small group of people."

Henry Tong Sau-chai, the chairman of the Hong Kong Council on Smoking and Health, said tobacco companies were the only beneficiaries if lawmakers decided to take a laid-back attitude on the issue.

Tong said there were misconceptions about such products, saying, "I once read that smoking e-cigarettes can improve your skin." He added that the council was introducing a new ambassador, Wise Mike, to debunk myths about tobacco products on social media.

However, Tong said the pandemic could be an opportunity to quit, as calls to the smoking cessation hotline doubled.

He suggested authorities expand the statutory no-smoking areas to bus stops and within 10 meters of elderly homes, schools and social welfare organizations and increase the tobacco tax.