Dozens of pro-Beijing politicians have staged a walk-out from the Hong Kong legislature to stall the swearing in of two pro-independence legislators in the Chinese-administered city.
The topic of independence has long been taboo in the former British colony, now governed under the "one country, two systems" principle since its return to China in 1997.
The government failed in an unprecedented legal attempt on Tuesday to halt the swearing-in of the two.
The politicians marched out of the legislative chamber, leaving Chinese and Hong Kong flags in their place, to deprive it of a quorum.
It is unclear when swearing-in will take place.
Al Jazeera's Sarah Clarke, reporting from the Legislative Council in Hong Kong, said: "In an unprecedented move, Hong Kong's Chief Executive C Y Leung has intervened in this whole process. He's trying to get two of the pro-democracy candidates disqualified from parliament.
"Leung's case is being mounted on the grounds that he believes last week's oath-taking was invalid and disrespectful to Hong Kong's basic law."
The government will formally challenge the decision of legislative authorities to allow Baggio Leung, 30, and Yau Wai-ching, 25, to retake their oaths in the High Court next month.
Yau and Leung sparked outrage among Hong Kong's pro-Beijing establishment when their first oaths were rejected by legislative officials last week.
'Hong Kong is not China'
Then they pledged allegiance to the "Hong Kong nation" and displayed a banner declaring that "Hong Kong is not China", using language some legislators portrayed as derogatory Japanese slang.
The pair are part of a new generation of Hong Kong activists determined to force issues of self-determination and independence on to the mainstream political agenda.
A judicial review will take place on November 3.
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Outside, hundreds of pro-Beijing protesters thronged the grounds of the legislature, some carrying placards of the pair dressed in Japanese army uniforms that denounced them as "traitors" and "dogs".
Others chanted that the pair must step down to protect China's "dignity".
The judicial review looms amid an unprecedented constitutional battle in the free-wheeling global financial hub, testing its rule of law and the separation of powers between the government and legislative branch.
Some senior judges and government officials fear privately that the issue could force Beijing to invoke rarely used powers to re-interpret Hong Kong's mini-constitution, or push through new laws.