Two organisations accused of subverting state power have been served with written notices from the government for a chance to make representations, as the security chief looks to exercise powers under Hong Kong's homegrown national security law to ban their operations in the SAR.

The Security Bureau on Monday said the Secretary for Security is considering whether to make orders under the Safeguarding National Security Ordinance to prohibit the operation or continued operation of the two groups – the "Hong Kong Parliament" and the "Hong Kong Democratic Independence Union".

Written notices were issued to the two organisations to allow them to "make representations before such orders are made", the bureau said in a statement.

"The two organisations in question aim to subvert state power," a bureau spokesperson said.

"Their objectives include promoting 'self-determination', making the 'Hong Kong Constitution', and overthrowing or undermining the basic system of the People's Republic of China established by the Constitution of the People's Republic of China or overthrowing the body of central power of the People's Republic of China or the body of power of the HKSAR."

The two groups would become "prohibited organisations" if the Secretary for Security decides to make orders to ban them, according to the bureau.

The spokesperson went on to say that it is an offence for anyone to act as an officer-bearer or a member of a prohibited organisation, participate in any activity or meeting of one, inciting any other person to become a member, and giving aid or procuring subscription or assistance for the group.

Those convicted face a maximum penalty of 14 years in jail and a HK$1 million fine.