Hong Kong Basic Law Article 23

Article 23 is an article of the Hong Kong Basic Law. It states that Hong Kong "shall enact laws on its own to prohibit any act of treason, secession, sedition, subversion against the Central People's Government, or theft of state secrets, to prohibit foreign political organizations or bodies from conducting political activities in the Region, and to prohibit political organizations or bodies of the Region from establishing ties with foreign political organizations or bodies."

The first attempt to implement the article was foiled by a massive street protest on 1 July 2003, when a half-million people marched through downtown Hong Kong. The law was pulled from consideration after division in the pro-Beijing camp and lost the majority of support in the legislature. China's National People's Congress imposed a national security law with similar language (though without the treason component) on Hong Kong on 30 June 2020, citing its authority under Article 18 of the Basic Law. A second attempt at implementing the article has undergone the legislative process. The bill was officially passed on 19 March 2024 and came into effect on 23 March 2024.