Justice chief Paul Lam said the recent resignations of overseas non-permanent judges from Hong Kong's top court would not undermine the city's rule of law.

Two UK judges – Lord Collins of Mapesbury and Lord Jonathan Sumption – resigned from the Court of Final Appeal earlier this month, and Beverley McLachlin from Canada said she would not stay on when her term expires at the end of July.

In an interview with RTHK marking the second anniversary of the current term of government, the secretary for justice said foreign legal experts were still confident in the SAR's judicial system, noting that two other overseas judges had joined the bench since the implementation of the national security law in 2020.

"I think it's normal for people to come and go. So, don't just focus on people leaving. There are also judges who are extending their terms and new judges who are joining," he said.

With the departure of the three judges, seven non-permanent judges from other common law jurisdictions remain at the Court of Final Appeal. The maximum number of non-permanent judges is 30.

Lam said there is no quota on the number of overseas non-permanent judges sitting on the top court.

"The Basic Law does not state that there must be eight or 10 non-permanent overseas judges on the court over a long period of time. I think quality is the most important. We are not looking at the numbers. In fact, we invite judges who are internationally prestigious and can help Hong Kong develop what is called jurisprudence, which is the quality of the law."

On the arrests made by the police in the past month over the publishing of social media posts ahead of a "sensitive date" for alleged sedition under Basic Law Article 23 national security legislation, Lam said the government is not targetting specific dates but the intention of an act.

"No matter what day or time it is, if your behaviour constitutes a crime with an incitement intent, then there's a risk you will be charged. We are targetting the words and actions. It doesn't matter what day. The day you come out and say you support 'Hong Kong independence' or want to subvert state power, there's a chance you violate the law," he said.