Beijing last month announced a plan to introduce legislation in Hong Kong to tackle secession, subversion, terrorism and foreign interference and which could see Chinese security agencies set up bases in the city.

Critics see the law as the most serious threat to a "one country, two systems" formula, agreed when the former British colony returned to Chinese rule in 1997, aimed at ensuring its freedoms and role as a global financial centre.

The Chinese government and Lam' s Beijing-backed city administration say the law will not curtail freedoms but will target a small number of "troublemakers" and help bring stability after a year of anti-government protests.

"I urge opponents who still use the usual tactics to demonise and smear the work to stop because by doing this they become the enemy of the Hong Kong people," Lam said before a cabinet meeting, referring to the legislation.

"The vast majority want to restore stability, and have safety, satisfaction and employment."

The government has mounted a campaign to rally public support for the legislation, with billboards, a booklet with questions and answers and a video of Lam defending the law "in the public interest".

In the video, posted on the city government's website, Lam decried a "terrorist threat" against a "traumatised" city, saying advocates of independence were "colluding with foreign forces" and undermining security.

"Hong Kong has become a gaping hole in national security, and our city's prosperity and stability are at risk," said Lam as she stood flanked by the Chinese and Hong Kong flags, the first bigger than the second.

Only a few protesters have been calling for the city's independence, a suggestion that is anathema to China.

Lam' s latest defence of the law came a year after Hong Kong's biggest ever demonstration, when about 2 million people, according to organisers, marched against another bill the city wanted to introduce that would have allowed extraditions to mainland China.

Critics saw that bill as a threat to judicial independence and although it was later withdrawn, protests broadened into a campaign for greater democracy and clashes with police intensified.

This year, the coronavirus outbreak brought a lull in protests but they have resumed since Beijing announced the plan for the security law.

Details have not been announced but it has been widely criticised, not only by democracy activists but by diplomats, lawyers and business leaders who also fear it could erode rights and freedoms.

Lam also said the government was considering relaxing restrictions aimed at stopping the coronavirus but it was unlikely they would be completely scrapped.

Hong Kong's borders are almost completely closed and groups are limited to eight people although life has largely returned to normal.

Trains, busses and ferries are once again packed at rush hour as most workers are back in their offices and schools have reopened. Night life has recovered most of its vibrancy.

The curb on gatherings has helped limit numbers at demonstrations, with police citing the coronavirus in rejecting applications for rallies, to the anger of democracy activists.

The government says the restriction has no political motive and is needed to stop the coronavirus. (Writing by Marius Zaharia Editing by Shri Navaratnam, Robert Birsel)

Australian Associated Press