Hong Kong police arrested 53 people on Wednesday on suspicion of subversion under the National Security Law. They were suspected of conspiring to pressure the special administrative region's chief executive to step down and paralyze the SAR government.

Those arrested were involved in a self-organized ballot by the opposition camp in July, ahead of the now-postponed Legislative Council election, to help the camp secure an absolute majority in the city's legislature. After that, they would veto the SAR government's annual budget indiscriminately and force the government to shut down due to lack of funding.

They include Benny Tai Yiu-ting, who initiated the campaign, former lawmakers Leung Kwok-hung, Alvin Yeung Ngok-kiu and Eddie Chu Hoi-dick, some sitting district councilors and some other activists.

Senior superintendent Steve Li Kwai-wah of the police's national security branch told a news briefing that among those arrested, six had organized and plotted the campaign and the others participated in it. The maximum penalty for subversion under the National Security Law is life imprisonment.

According to the police, the idea to paralyze the government was floated in March. In April, the activists formed solid plans-to gain 35 seats and above and veto the financial budget twice to stop the government operating.

In June, they set election dates and started crowdfunding and promotion via social media platforms and forums. Despite the government's warning that the plan was potentially subversive and may be a violation of the National Security Law, the informal ballot was held on July 11 and 12, and the result was announced on July 13. The organizer claimed about 610,000 local residents voted.

Senior superintendent Li said the plan was executed step by step with strong determination and abundant resources, adding that the only goal was to paralyze the government, which violated Article 22 of the National Security Law. Yet he stressed that police would not launch criminal investigations into voters.

Article 22 stipulates that any person who organizes, plans or participates in acts that undermine the central government's or the HKSAR's body of power to perform duties by unlawful means with a view to subverting State power shall be guilty of an offense.

With court warrants, police searched 72 locations across the city and ordered four companies to turn in necessary documents related to the case, Li said. In addition, police froze assets amounting to HK$1.6 million ($206,400) in relation to the case.

Prior to Wednesday's arrests, at least 40 people had been arrested under the National Security Law since it was implemented on June 30 last year, including Jimmy Lai Chee-ying, founder of Next Media, which owns Hong Kong newspaper Apple Daily.

Following the arrests, the Liaison Office of the Central People's Government in the HKSAR and the Office for Safeguarding National Security of the Central People's Government in the HKSAR, in separate statements, expressed support for the police action.

A spokesperson for the liaison office said in its statement that the implementation of the National Security Law is a turning point for the city to restore order. Only strictly enforcing the law can guarantee the long-term stability of society and the sound and sustained implementation of "one country, two systems", it said.

In a statement issued on Wednesday afternoon, the Hong Kong SAR government stressed it had zero tolerance for subversive acts and that it would take deterrent actions as necessary.

Meeting the press on Wednesday, Secretary for Security John Lee Ka-chiu said the ballot was part of a vicious plan devised by a group of activists to paralyze the Hong Kong government. If the plan had gone through, Hong Kong would have suffered incalculable losses and been thrown into an abyss, Lee said.

Some lawmakers-such as Holden Chow Ho-ding, Elizabeth Quat Pui-fan and Leung Checheung from the Democratic Alliance for the Betterment and Progress of Hong Kong, and Alice Mak Mei-kuen from the Hong Kong Federation of Trade Unions, also said the police action was necessary and justified. They added that manipulation of legislative election cannot be tolerated.

Local barrister Lawrence Ma Yan-Kwok stressed that Hong Kong lawmakers' power of voting on bills cannot be abused.