Stamps that validate that duty payments for specified tobacco products have been made will be mandatory on retail packaging as part of a looming further crackdown on illicit cigarettes.

The sale of tobacco products, such as a packet of cigarettes, that come without such stamps or with counterfeit stamps will be criminalised, with offenders facing up to a HK$2 million fine and seven years' imprisonment.

That would mark a jump from the existing fine of up to HK$1 million and prison term of two years for smuggling.

As part of a wider crackdown, inbound travellers found carrying more than the permitted number of duty-free cigarettes would be subject to a bigger fine of HK$5,000 in future.

Currently, those who bring in more than 19 sticks of undeclared cigarettes for personal use are subject to a fixed penalty of HK$2,000.

That jump in fines and prison terms is among a series of anti-smoking measures in a bill gazetted on Friday, with officials also planning to ban smoking in public transport queues.

Another anti-smoking proposal is to bring in subsidiary laws stipulating that all cigarette packages have to be uniformly designed, using only one standard colour.

There will also be restrictions or prohibitions on "displaying any logos, colours, brand images or promotional information on the packaging other than brand names and products names displayed in standard colour and font style, thereby dampening promotion effects," the Health Bureau said in a document submitted to the legislature.

It added that the idea is to have the changes for both the duty stamp system and standard packaging implemented in the second quarter of 2027.