China’s top legislative body added Hong Kong’s security legislation to its latest agenda, NOW TV reported, signaling Beijing may soon hand down a still-secret measure that pro-democracy activists and business groups say could erode the city’s unique freedoms.

The National People’s Congress Standing Committee planned to discuss the legislation to punish acts of secession, subversion, terrorism and collusion with foreign forces at a meeting beginning on Sunday, NOW TV said. One participant in the discussions, Maria Tam, told a Hong Kong radio station Friday that the body was "very likely” to pass the law before the three-day session’s scheduled conclusion on Tuesday.

Chinese President Xi Jinping’s government announced plans in late May to impose the legislation on the former British colony following an unprecedented wave of protests last year. If the proposed law passes during this NPC session, it could come into effect in time for the symbolic July 1 anniversary of the city’s return to Chinese rule in 1997.

Pro-democracy politicians and foreign governments including the U.S. have criticized the proposed law as a blow to the "one country, two systems” principle that keeps Hong Kong’s legal system separate from the mainland. About 56 percent of residents oppose the legislation, compared with 34 percent who support it, according to a Reuters/Hong Kong Public Opinion Research Institute poll released Friday.

Hong Kong officials have defended the new law as necessary to maintain social stability after last year’s protests, despite acknowledging they haven’t seen the full proposal. Details released by state media last week showed that Beijing planned to set up a local intelligence bureau, take control of some sensitive cases and remove the court’s ability to select judges on security matters.