Hong Kong’s leader has strongly endorsed the new security law China’s central government is imposing on the semi-autonomous territory in her speech marking the anniversary of its handover from colonial Britain.
“This decision was necessary and timely to maintain Hong Kong’s stability,” Carrie Lam said.
The national security law targets secession, subversion, terrorism and colluding with foreign forces with punishments up to life in prison.
Acts of vandalism against government facilities or public transport can be prosecuted as subversion or terrorism, while anyone taking part in activities deemed as secessionist would also be in violation of the new law.
The law directly targets some of the actions of anti-government protesters last year, which included attacks on government offices and police stations, damage to subway stations, and the shutdown of the city’s international airport.
The new national security law further blurs the distinction between the legal systems of semi-autonomous Hong Kong, which maintained aspects of British law after the 1997 handover, and the mainland’s authoritarian Communist Party system.
Its passage comes after Hong Kong’s legislature in early June made it illegal to insult the Chinese national anthem.
Boris Johnson said on Tuesday the UK government is "deeply concerned" by the legislation, adding "we will be setting out our response in due course".
A pro-democracy political party, The League of Social Democrats, organised a protest march during the flag-raising ceremony preceding Ms Lam’s speech.
Participants chanted slogans echoing demands from protesters last year for political reform and an investigation into alleged police abuses.
President Xi Jinping signed a presidential order making the law take effect after its approval by the Standing Committee of the National People’s Congress, China’s rubber-stamp legislature, and it has been added to the Basic Law, Hong Kong’s constitution.
Legislative Councillor for Hong Kong, Tanya Chan, warned the new law is a "white terror" that could spread to all areas of life on the island.
"I think this white terror will spread to all aspects of our normal lives and will affect not only the politicians, it will also affect normal families with kids," she told ITV News. "Because based on the definition of national security in China, under the legislation, you can see this has very wide coverage. "For example, economies, education, religion and all these will be affected so I’m easily worried about how far it can go. "It seems that this piece of law is targeting just a small number of people but I don’t think so because, as I’ve mentioned it’s like a white terror - it will just spread on and will affect different types of people."