Hong Kong(CNN) A primary election held by Hong Kong's democratic opposition may have been illegal under the new security law, China said Monday, in a statement that shows how far the goalposts have moved just two weeks after the sweeping legislation was imposed on the city.
More than 600,000 people took part in the vote over the weekend, designed to narrow down the number of pro-democracy candidates in September elections to the city's legislature. Similar efforts have been tried in previous years, but this was the most organized yet, as the opposition aims to seize a historic majority in spite of recent obstacles, not least the new security law.
Imposed by Beijing on the city on June 30, the legislation criminalizes secession, subversion, terrorism, and collusion with foreign forces. Officials previously said it will affect a tiny handful of Hong Kongers, while critics pointed to its broad scope and ill-defined offenses as reason for alarm.
In a statement late Monday, the Liaison Office, Beijing's top representative to Hong Kong, said the primary election contravened the law -- raising the possibility hundreds of thousands of people were now implicated in an offense.
"With the support of external forces, opposition groups and leaders have deliberately devised plans to hold this so-called 'primary election,' which is a serious provocation to the current electoral system and caused serious damage to the fairness and justice of the Legislative Council elections," the Liaison Office said.
The statement came after the Hong Kong government said it was "conducting an in-depth investigation" into the primary, and would "immediately refer the case to relevant law enforcement agencies" if there was any illegal activity.
One chief complaint of the government was organizers' stated goal of achieving a 35-seat parliamentary majority, allowing the opposition to block legislation and potentially force the resignation of Chief Executive Carrie Lam.
"If this so-called primary election's purpose is to achieve the ultimate goal of delivering what they called '35-plus' with the objective of objecting or resisting every policy initiative of the HKSAR government, it may fall into the category of subverting the state power -- one of the four types of offenses under the national security law," Lam said Monday.
The Liaison Office statement went further, accusing Benny Tai, the onetime leader of the 2014 pro-democracy Umbrella Movement and organizer of the primary, of scheming to "seize the governance of Hong Kong and stage a 'color revolution'."
"Who instructed (Tai) to openly manipulate the election in so high-profile a manner? Who gave him such confidence?" the statement added, without providing evidence or suggestion of who Tai was supposed to have colluded with.
Tai, who could not immediately be reached for comment, could face at least 10 years and up to life imprisonment if found guilty under the security law of colluding with a foreign power in "rigging or undermining an election."
Nor might he be the only person punished. Antony Dapiran, a Hong Kong-based lawyer and author of "City on Fire: The Fight for Hong Kong," predicted that after Beijing's statement declaring the primary illegal, the government may move to "disqualify all candidates selected through the primary process (maybe even all who ran in the primary)" from September's election.
Preliminary results from this weekend's primary appear to show many younger, protest-linked candidates ahead of traditional pro-democrats, after similar success in last year's local elections, in which a large number of first-time candidates were elected in a landslide defeat of pro-government parties.
Tai said the turnout showed that "Hong Kong people have demonstrated to the world, and also to the authorities, that we have not given up to strive for democracy."
Beijing's assertion that the primary undermines September's vote creates a bar that few democracies could clear. Primary vote are regularly held to narrow down candidates for a general election, nor do they always involve members of one party: Bernie Sanders, who won the second-most votes in the United States Democratic Party presidential primary, is an independent.
In many democracies, parties go even further in seeking to avoid splitting the vote. During last year's general election in the United Kingdom, multiple anti-Brexit parties formed an election pact, choosing not to field candidates in seats where that might have resulted in a pro-Brexit party winning.
"Elections are a very serious and solemn matter in every jurisdiction," Lam said this week. "People have to uphold their right to be able to cast a vote in an election which is open, fair and honest."
Mainland China does not have free and fair elections, or mass votes of any kind. In Hong Kong, this year's legislative election was seen as perhaps the final chance for the democratic opposition to win any significant power.
Before the security law was passed, multiple candidates had already been barred from standing and lawmakers removed from parliament. Officials had also suggested that anyone who campaigned against or criticized the security law could face being struck off the ballot.
In the hours after it became law, multiple political parties disbanded -- including one founded by prominent activist Joshua Wong. Other groups, particularly pro-independence parties, moved their operations overseas, for fear of arrest.
CORRECTION: This story has been corrected to reflect that Beijing imposed the new national security law on June 30.