Hong Kong's pro-democracy political bloc was wiped out Wednesday as 15 legislative assembly members resigned in protest over the disqualification of four of their colleagues by the central government.

Members of the Legislative Council who "refuse to recognize the state's ownership and exercise of sovereignty over Hong Kong" or "engage in other acts that endanger national security" will immediately lose their qualifications, the government said Wednesday.

The announcement was preceded by a resolution passed by the National People's Congress in Beijing requiring "patriotism" from all Hong Kong lawmakers.

"Hong Kong, from today onward, can longer tell the world that there is 'one country, two systems'," Democratic Party member Wu Chi-wai said Wednesday.

"There is separation of powers under the Basic Law but, today, the central government's decision means separation of powers will be taken away," Wu said and called Hong Kong chief executive Carrie Lam a "puppet" of mainland China.

Members of the city's pan-democratic bloc chanted "add oil" - a common local refrain of encouragement - in a late Wednesday news conference to announce the mass resignation. They had threatened earlier in the week if their colleagues were disqualified.

The four lawmakers at the center of the dispute are Civic Party's Alvin Yeung Ngok-kiu, Dennis Kwok and Kwok Ka-ki and Kenneth Leung from the Professionals Guild.

"It's my honor having served as a Hong Kong legislator," Civic Party member Yeung said Wednesday after learning he would be forced to step down. "I might not be given the same opportunity in the future but I have faith the talented and courageous youth will help build our city for the better."

Yeung and his three colleagues were banned from running for reelection during the September Legislative Council elections - which were delayed owing to the pandemic - for failing to uphold the Basic Law.

"These four are legally determined to not sincerely support the Basic Law and hold allegiance to the Hong Kong Special Administrative Region of the People's Republic of China," city leader Carrie Lam said at the time.

But because the election was postponed the quartet had been required to continue in their positions. This ended Wednesday after the National People's Congress formally disqualified them from serving as assembly members in Hong Kong.

"I understand and respect" the decision reached by the People's Congress, assembly president Andrew Leung said late Wednesday.

He spoke in favor of political unity, calling on "assembly members across the political spectrum to adopt a pragmatic approach in striving for the best interest of the community."