The pro-Beijing block says the law is necessary for Hong Kong to show appropriate respect for the anthem. Those found guilty of intentionally abusing the “march of the volunteers” would face up to three years in prison and fines of up to $6,450.
Hong Kong's legislature voted on Thursday in favour of a controversial bill that would criminalise abuse of China's national anthem.
The pro-democracy camp sees the anthem law as an infringement of freedom of expression and of the greater rights that residents of the semi-autonomous city have compared to mainland China.
Protests are expected outside the legislature.
What is the law?
Hong Kong’s National Anthem Bill, when passed into law, will govern the use and playing of the Chinese national anthem.
This includes provisions that threaten to punish those who insult the anthem with up to three years in jail and/or fines of up to $6,450.
The bill states that "all individuals and organisations" should respect and dignify the national anthem and play it and sing it on "appropriate occasions". It also orders that primary and secondary school students be taught to sing it, along with its history and etiquette.
Why is it controversial?
Anti-government protests last year were primarily aimed at resisting further integration with mainland China. The Chinese national anthem has been booed at several events, including football matches.
Protesters and anti-Beijing politicians say the bill represents the latest sign of what they see as accelerating interference from Beijing in the freewheeling former British colony.
Britain handed Hong Kong back to Chinese rule in 1997 with guarantees that the city's core freedoms and way of life would be protected under a "one country, two systems" formula, which Beijing says it respects.
The freedoms of speech, press, association and demonstration are explicitly written into the Basic Law, the mini-constitution that guides Hong Kong’s relationship with China, its sovereign power.
Opponents of the bill say those freedoms are now under threat.
More technically, some senior lawyers fear the bill is highly unusual in that it, in part, reflects the ideological aspirations of China's Communist Party that might prove difficult to enforce.
"It is the first Hong Kong law I've seen that looks like it was written in Beijing," one senior judge told Reuters recently, speaking privately. "It will be a nightmare to rule on."
The Hong Kong Bar Association acknowledged the need for such laws but said parts of the bill "deviate from the good traditions" of Hong Kong’s common law system.
It said there was a fundamental difference between that system and the "socialist legal system of mainland China which would include political ideology and conceptual guidance".
The law is coming on the heels of another controversy: China's decision to impose a national security law in Hong Kong.
Where did it come from?
For years, Chinese officials and their pro-Beijing allies in Hong Kong have wanted to instil a greater sense of patriotic pride across its freest, and most restive, city.
Hong Kong's government says the bill reflects the city's own legal system and situation.
"The main spirit of the … bill is 'respect', which bears absolutely no relations to 'restricting freedom of speech' as claimed by certain members of the community and definitely not a so-called 'evil law'," a spokesman said earlier this year.
Protests over the bill's passage are widely expected.
The government, under pressure from Beijing, has prioritised passing the bill into law before the end of this four-year legislative session in July.
Having been mired in a log-jam of legislative procedural battles, voting on the bill got underway on Thursday.
If the bill becomes law and is enforced, constitutional challenges can be expected in courts – both into the bill's content, and the procedural battles through which it passed.