In June 2020, the NPCSC unilaterally imposed the sweeping Hong Kong national security law to criminalise "separatism, subversion, terrorism and foreign interference" which many interpreted as a crackdown on civil liberties, government critics, and the independence movement. In July, the pro-democrats organised a territory-wide primary election to maximise their chance to obtain a majority in the upcoming Legislative Council election, despite the government warning of their potentially breaching the national security law as some of the candidates vowed to vote down the government budget in order to pressure the administration to respond to the demands of the protesters. Chief Executive Carrie Lam abruptly invoked the Emergency Regulations Ordinance to postpone the election, citing the recent resurgence of the COVID-19 cases. However the decision was widely seen as the latest in a rapid series of aggressive moves by the Beijing authorities to thwart opposition momentum and neutralise the pro-democracy movement. The 55 organisers and candidates in the primary were later arrested under the national security law on 6 January 2021, making it the largest crackdown under the national security law since its passage.