It is the responsibility of both the government and the community to educate misinformed youths about China's sovereignty over Hong Kong, the chief executive of the Hong Kong Special Administrative Region, Leung Chun-ying, said on Tuesday.

Leung told reporters before a Tuesday Executive Council meeting that the region's Basic Law says Hong Kong's economic system and way of life will remain unchanged until 2047, there is no time limit on China's sovereignty.

Leung's remarks came in response to the notion of a poll on independence sought by student activists and opposition political figures. He said young people must be clear about the seriousness of China's sovereignty and territorial integrity.

During an address at the Hong Kong Foreign Correspondents' Club on Tuesday afternoon, Wang Zhenming, head of the legal department of the central government's Hong Kong Liaison Office, took aim at the way freedom of speech was being used to justify the poll, saying that reasonable limits on speech are boundaries that help avoid "unaffordable consequences".

Wang said that while freedom of speech is protected by the Basic Law in the SAR and in China's Constitution, reasonable limitations on speech are necessary and commonplace in other countries and regions.

Wang, who is dean of the Tsinghua University School of Law, referenced the Hong Kong Court of Final Appeal's 1999 ruling in a flag-burning case that freedom of speech was not unlimited.

Wang said suggestions by independence agitators would create conflict and social instability - not to mention that the very prospect of independence was not achievable.

Basic Law Institute Chairman Alan Hoo said advocating for Hong Kong independence may violate Crimes Ordinance provisions regarding treason, sedition and incitement.

Hoo said the stated goal of Demosisto, one of the parties organized by student activists, was to decide Hong Kong's future through a referendum, which may violate the law.

"Establishing a party to advocate an illegal platform is an obvious action," Hoo cautioned. "One cannot pretend it is merely freedom of expression."

Contact the writers at tim@chinadailyhk.com