Among them is Nathan Law, the leader of the pro-democracy Umbrella Movement, which led large street protests in 2014 demanding electoral reform and greater autonomy from Beijing.
The High Court ruling was based on the guidelines issued in November by China's legislature, the National People's Congress (NPC), after the swearing in had taken place in October.
In the guidelines, Beijing said that oaths must be taken in a "sincere and solemn" manner, particularly the part of the oath that pledges allegiance to China.
The four disqualified lawmakers had done quite the opposite when they were sworn in.
Leung Kwow-hung brandished a yellow umbrella, symbol of the 2014 Umbrella Movement protests. Lau Siu-lai read her oath very slowly, taking nearly 10 minutes to finish. And Edward Yiu called for universal suffrage. All acts that were considered “improper” by Beijing.
However, these four disqualifications were not the first. In November, two pro-independence lawmakers were ejected from parliament for swearing allegiance to the “Hong Kong nation” in their oaths, and for using a derogatory term for China.
Why Beijing was able to intervene
“The government of China, through its NPC, has the constitutional right to provide interpretations of Hong Kong’s Basic Law, which is Hong Kong's constitution” explains Steve Tsang, director of the China Institute at London Metropolitan University’s School of Oriental and African Studies (SOAS).
“That authority exists properly and has already been exercised on different occasions.”
However, this is the first time Beijing has provided a special interpretation and required it to be applied retrospectively.
Tsang notes that the way in which the interpretation was handed down, after the swearing in had taken place, “appears to be the application of retrospective legislation to make an act that had already been committed before the law was changed, illegal.”
Normally you change the law, and after the law is changed, you can’t do certain things,” Tsang explains. “Now they’re saying ‘you’ve done something, we don’t like it, so now we have an interpretation to kick you out of elected office.”
That’s a pretty major change,” he says.
What next for the pro-democracy movement?
Demosisto, the pro-democracy party of which Law is chairman, said in a statement it “condemns the manifest interference of the Beijing government to cripple Hong Kong’s legislative power through reinterpretation of the Basic Law.”
We implore Hong Kong citizens to acknowledge the significance of this judgment and mobilise to prevent further intervention and political persecution against other pro-democracy legislators.”
The pro-democracy camp in parliament has lost six seats so far, but it still holds on to roughly 20 out of parliament’s 70 total. However, it has lost its veto power over major legislation, a major loss for the camp.
The ruling represents a “risk of changing the balance of power in parliament in favour of the pro-establishment parties, even more than before,” says Jean-Pierre Cabestan, professor of political science at Hong Kong Baptist University.
“What we need to wait for are the results of the by-elections,” he explains.
By-elections to fill the seats left vacant by ejected lawmakers in parliament are supposed to be held 21 days after all appeals have been exhausted. This process, however, could take months.
Theoretically, the pan-democratic camp could win back its seats in these by-elections. But Professor Cabestan has his doubts.
“What I’m worried about is that the Beijing authorities may find other legal excuses to get rid of the pro-democracy lawmakers within the parliament,” he says. “That’s the risk in the long term.”
For Cabestan, the ruling “will contribute to polarising political life in Hong Kong even more than before.”