Beijing will hand down its fifth interpretation since 1997 of Hong Kong's Basic Law or mini-Constitution on Monday, in a move seen as intervening in the city's politics.
The central government is said to be seeking to bar two pro-independence lawmakers in the city from retaking their swearing-in oath, after their first was invalidated as they had altered some words and pronounced China as "Cheena", seen as demeaning to the mainland.
Beijing yesterday informed the High Court - which on Thursday heard a judicial review brought by the government against the Legislative Council (Legco) president's decision to allow the pair from Youngspiration to retake their oath - that it would interpret the Basic Law.
While Hong Kong is part of China, it has been guaranteed a high degree of autonomy under the "one country, two systems" framework after the city was returned to China in 1997. Beijing's initiative to interpret the Basic Law before the local court ruling erodes the city's autonomy and undermines its judicial independence, said Hong Kong lawyers, who will hold a silent protest march next Tuesday.
The order to interpret Article 104, which states that lawmakers need to swear allegiance to Hong Kong as part of China, came from Mr Zhang Dejiang, chairman of the National People's Congress (NPC), China's Parliament.
On Oct 12, Ms Yau Wai Ching, 25, and Mr Sixtus Leung, 30, had their swearing-in oaths invalidated by the Legco president as they had displayed a banner that read "Hong Kong is not China" and altered the wording of their oaths, including derogatory terms and expletives.
Political observers said the actions of the duo have given Beijing a chance to kick them out of the Legco. Ms Yau and Mr Leung were elected in the Sept 4 polls where they had campaigned for a stronger Hong Kong identity and separation from the mainland.
Beijing has been watching Hong Kong closely after the Mongkok riot in February, where young radicals had been prominent.
After several young radicals were voted into the Legco in September, Beijing saw the need to put a stop to Hong Kongers seeking separation from China, said political scientist James Sung. He added that Beijing's interpretation of the Basic Law goes beyond dealing with the current oath-taking row.
"Beijing wants Hong Kongers, especially the younger generation, to have a broader interpretation of what it means by loyalty, separatism, self-determination and, of course, independence. The central government wants to let Hong Kongers know its bottom line," said Prof Sung.
"Currently, the Hong Kong court has no legal instrument or any law at hand to deal with independence issues."
"They (Ms Yau and Mr Leung) have made a wrong judgment on the reactions from Beijing," added Prof Sung, who expects a by-election to take place within six months to fill the empty seats. Yesterday, the pair dismissed claims that their actions have triggered the interpretation. Both said they do not regret what they had done.
Lawmaker Dennis Kwok argued that Article 104 is clear and straightforward and he does not see "any room for interpretation".
Under Article 158 of the Basic Law, the NPC Standing Committee has the power to interpret the Basic Law and its opinions are final and legally enforceable.