A pro-independence political party in Hong Kong has been officially banned by the government. The controversial decision was taken by Hong Kong’s secretary for security John Lee.

The decision, which was published in government’s legislative gazette, has been strongly criticised by rights groups and pro-democracy politicians for curbing freedom of speech in the city.

As reported by the Agence France-Presse (AF), the government used colonial-era legislation once used to target “triad” criminal gangs in the city.

“I hereby order that the operation or continued operation of the Hong Kong National Party (HKNP) in Hong Kong be prohibited,” the statement said, taking immediate effect from September 24.

The move comes after Hong Kong police said the HKNP and its leader Chan Ho-tin, also known as Andy Chan, posed an “imminent threat” to China’s territorial integrity and national security, because Chan had refused to rule out the use of force or civil disobedience.

According to AFP, police gathered more than 700 documents as “evidence” that the party’s aims of building a republic of Hong Kong and abolishing its mini-constitution, the Basic Law, are in violation of its first principle; that Hong Kong is an administrative region of the People’s Republic of China.

Police listed Chan’s pro-independence activities, which include “infiltrating” secondary schools via his party’s “political enlightenment” programme, publishing articles, taking part in elections to the Legislative Council (LegCo), and various fund-raising and campaigning activities on the streets of Hong Kong.

“I hope people will now realize that there are only two choices: to become a municipality under the direct control of Beijing, or independence for Hong Kong,” said Chan. “I would choose independence for Hong Kong.”

“People will only look for another solution when they realize that ‘one country, two systems’ isn’t working,” Chan said, in a reference to the formula agreed for Hong Kong’s 1997 handover to Chinese rule that promised the city a “high degree of autonomy.”

In a Statement by the Spokesperson, it is underlined that freedom of expression and association are fundamental rights guaranteed by Hong Kong’s Bill of Rights and the International Covenant on Civil and Political Rights and should be protected.

“The order by the Security Secretary of the Hong Kong Government to ban the Hong Kong National Party limits the freedom of expression and association, as well as political activity in Hong Kong, and risks having a wider negative impact. The European Union fully abides by its ‘One China’ policy and supports the ‘one country, two systems’ principle,” the Spokesperson stated.