Hong Kong's legislature has approved a new rule to restrict foreign lawyers from dealing with court cases linked to national security.

The Legislative Council on Wednesday passed an amendment to an ordinance related to the matter.

The change stipulates that foreign lawyers cannot handle national security cases without permission from the territory's chief executive.

In Hong Kong, foreign lawyers have been allowed to participate in legal cases if certain conditions are met under its judicial system introduced during Britain's colonial rule.

But the local government strongly opposed the participation of a Britain-based lawyer in the trial for Jimmy Lai -- founder of the now-defunct pro-democracy Apple Daily newspaper. Lai was charged with violating China's national security law for Hong Kong, among other counts.

The Hong Kong government asked the Standing Committee of China's National People's Congress for a legal interpretation concerning the matter. In December last year, the committee said officials including the chief executive decide on whether to allow foreign lawyers to deal with court cases.

Associate Professor Hiroe Noriko at Daito Bunka University in Japan, who studies Hong Kong's legal system, said the territory's judicial independence, which has been protected under the "one country two systems" principle, has become further nominal.