Hong Kong disqualified four opposition members of its legislature on Wednesday shortly after the Chinese parliament adopted a resolution allowing the city's executive to expel legislators without having to go through the courts.
The expulsion of the four from Hong Kong's Legislative Council, the former British colony's mini-parliament, deals a further blow to pro-democracy politicians in China's freest city.
The 19 democratic members of the 70-seat city legislature on Monday threatened to resign en masse if any of them was disqualified, saying that would reflect their unity and show how far Beijing was willing to go to crush opposition.
While the assembly is controlled by the pro-Beijing camp, the opposition's resignation would turn it into a rubber stamp.
The opposition members have tried to make a stand against what many people in the former British colony see as Beijing's tightening grip over the financial hub, despite a promise of autonomy.
China denies encroaching on Hong Kong's freedoms but authorities in Hong Kong and Beijing have moved swiftly to stifle dissent after anti-government protests flared in June last year and plunged the city into crisis.
The city government said in a statement the four legislators - Alvin Yeung, Dennis Kwok, Kwok Ka-ki and Kenneth Leung - were expelled from the assembly for endangering national security. It did not elaborate.
They were among 12 legislators who were earlier disqualified from standing in a legislative election, now postponed, for various reasons including collusion with foreign forces and opposition to the new national security law.
The disqualifications are likely to add to concern in the West about Hong Kong's autonomy, promised under a "one country, two systems" formula when Britain handed it to China in 1997, as Joe Biden prepares to take over from Donald Trump as US president, promising to promote democracy around the world.
The decision by the Chinese parliament's top decision-making body comes amid frustration in pro-Beijing circles in Hong Kong over what they see as opposition "delay tactics" to obstruct legislation.
Filibustering has long been common in Hong Kong where only half of the 70 seats in the legislature are elected and the other half stacked with pro-Beijing figures.