Four democratically elected lawmakers are at risk of being unseated for the same offenses.
On Sunday, the director of China's liaison office in Hong Kong, Zhang Xiaoming, said in an interview with state broadcaster CCTV that Beijing will not tolerate attempts to use Hong Kong as a base for rebellion.
"Hong Kong should never allow anyone to do any forms of activities that are harmful to China's sovereignty and security, to challenge the powers of the central government and the authority of the HKSAR Basic Law, or to take advantage of the HKSAR to engage in infiltrative and subversive activities to sabotage the social and political stability of the Chinese mainland," Zhang said.
"These are the three bottom lines."
Meanwhile, Zhang emphasized that the 'One Country, Two Systems' policy has been successfully implemented, that this success was "universally acknowledged" and leaves no space for separatist mindset.