The Law Society on Tuesday set out its submission to the government's consultation on Basic Law Article 23 legislation, saying it's possible to balance national security with human rights.

The solicitors' body called on officials to clarify the definition of "acts with seditious intention", so political speeches or other forms of expression aren't covered by the offence.

On the idea of a public interest defence for charges of espionage or leaking state secrets, society president CM Chan said Canadian law provides a good reference.

"I think the Canadian model at least provides a suitable mechanism for this matter to be considered. There is a procedure to be followed," he told reporters at a press conference.

"There's an application to the government. If the government fails to respond, then the person may use public interest defence as a defence."

The society also said that it's natural that the business community would like a clear definition of what constitutes a state secret.

"For example, social development, the concept; technological development; whether these will form part of state secrets. So these are the things that I have been asked quite often by foreign investors," Chan said.

In the consultation document, the government points to legislation in the UK that empowers the police to ban suspects from consulting certain lawyers.

On this, Chan noted that it's a constitutional right for Hongkongers to choose their own lawyers, saying the Law Society "will definitely request that this right cannot be taken away".

The Law Society chief added that since the consultation document only covers general legal principles, the society will offer views on matters such as sentencing levels when the administration tables a bill on the legislation to Legco.