Lawsuits were filed Friday against four pro-democracy legislators, including former Umbrella Movement protest leader Nathan Law, days after a court upheld the barring of two of their colleagues.
Following the move, pro-democracy politicians marched on the office of the city's top official, Chief Executive Leung Chun-ying, bearing banners reading "CY launching a coup, declaring war on voters."
Yau Wai-ching and Baggio Leung were barred from taking their seats in the city's parliament after a court ruled that their oaths of office, during which they swore and displayed a banner reading "Hong Kong is not China," were invalid.
The pair told CNN last month
that they would continue to fight the ruling in order to "protect our system and the separation of powers and the rule of law."
The ruling against them came after the dramatic intervention of Beijing, which employed a rarely-used power to re-interpret Hong Kong's Constitution
and rule that oaths must be taken "sincerely and solemnly
Pro-democracy lawmakers have traditionally used the swearing-in ceremony as a venue for protests, though few took it as far as Yau and Leung's curse-laden speeches.
Law quoted Gandhi before making his oath: "You can chain me, you can torture me, you can even destroy this body, but you will never imprison my mind."
Many commentators saw the new requirement for sincerity and solemnity, which does not appear in the mini-constitution
, as a means to go after more anti-government lawmakers. Those fears were confirmed this week.
Law was one of the leaders of the Umbrella Movement, which saw hundreds of thousands of Hong Kongers take to the streets to demand greater political freedom. At 23, he is also the youngest person ever elected to the city's parliament
Veteran lawmaker "Longhair" Leung Kwok-hung, sociology lecturer and activist Lau Siu-lai and architect Edward Yiu are also targeted.
In a statement, the Justice Department said it has begun legal proceedings "asking the court to declare (the lawmakers') oaths invalid and to leave their posts vacant."
The decision to sue the four lawmakers, all of whom have been consistent critics of government policy, "was driven by legal and law enforcement considerations, without political considerations," the statement said.
Law charged that the move was an "orchestrated attack" by the government "against all democrats and all voters supporting democracy," to take full control of the city's parliament, or LegCo.
While Legco is dominated by pro-government lawmakers due to the city's undemocratic functional constituency system
, at present, pro-democracy parties do possess enough seats to block certain laws that require a more than two-thirds majority to pass.