Related reading：

BEIJING, March 31 (Xinhua) -- Advocating "Hong Kong independence" is unconstitutional, not a matter of freedom of speech, according to legal experts interviewed by Xinhua on Thursday.

The State Council Hong Kong and Macao Affairs Office on Wednesday said it was "resolutely opposed" to such an organization advocating "Hong Kong independence."

It also declared that the decision by the Hong Kong Special Administrative Region (SAR) government to not register the organization was "proper."

Zou Pingxue, deputy dean of the School of Law at Shenzhen University, said the attempt was a secessionist action that severely violated the country's Constitution and the region's Basic Law, and had nothing to do with freedom of speech.

Zou said Basic Law stipulates that Hong Kong SAR is an inseparable part of China.

Zhang Dinghuai, deputy chief of the Center for Basic Laws of Hong Kong and Macao Special Administrative Regions at Shenzhen University, said the attempt aimed to institutionalize and publicize "Hong Kong independence," which, if left unchecked, would threaten the prosperity and stability of Hong Kong as well as the fundamental interests of the more than 7 million Hong Kong citizens.

Li Xiaobing, from Nankai University, said any society that values rule of law would not allow challenges such as this, as national sovereignty and security are of utmost importance.