The senior counsel said people were wrong to argue that the law would undermine Hong Kong's freedoms given that they hadn't actually seen a final draft of the legislation yet.

"The US Secretary of State, (Mike) Pompeo said immediately after the decision was passed that it represented a 'death knell' for the freedoms of Hong Kong," Tong said on RTHK's Letter to Hong Kong programme..

"Opposition leaders in Hong Kong announced 'the death of One Country, Two Systems' and the rule of law. And none of them have even seen the proposed legislation.

"The process of lawmaking is yet to begin. The SAR government has already said it would do its utmost to truly reflect the sentiment of people of Hong Kong to the (National People's Congress Standing Committee).

"However the new law is written, when it becomes law in Hong Kong, the whole weight of the common law system will be there to ensure justice is done and seen to be done.

"I have every confidence it will be so and those who have witnessed how our judiciary works will no doubt share the same confidence."

Tong also rejected suggestions that the imposition of a security law went against the Sino-British Joint Declaration, which set the framework for Hong Kong's 1997 handover, and the promised "high degree of autonomy".

"If you read the declaration, nowhere does it refer to any matter relating to national security, let alone that “high degree of autonomy” includes a right to allow people in Hong Kong to undermine national security of the mother country," Tong said.

"The same is true in relation to China’s “Basic Policies Regarding Hong Kong” included as an annexe to the declaration."