Joshua Wong, who became prominent as a teenage activist during the 2014 Umbrella protests, took to Twitter to confirm the news.

"I was just disqualified from LegCo election, despite being the biggest winner in #Hkprimaries. Few minutes ago, I was just disqualified from running in the upcoming LegCo election in #Hongkong, even though I got the highest vote share in the primary, w/ 30000+ votes obtained," Wong tweeted.

According to Wong, his candidature was cancelled as he described the new national security law as draconian.

"The excuse they use is that I describe #nationalsecuritylaw as a draconian law, which shows that I do not support this sweeping law," he added.

According to the government, a candidate will not be allowed to contest the elections if he or she indulges in promoting or advocating Hong Kong's independence; wanted foreign powers or government to intervene in the region's politics; protested against Beijing.

"There is no question of any political censorship, restriction of the freedom of speech or deprivation of the right to stand for elections as alleged by some members of the community," a government statement read. 

The Hong Kong LegCo or Legislative Council is made up of 70 seats. The public directly votes for 35 seats.

"Another 30 seats represent "functional constituencies" - these are voted for by smaller groups representing special interests, primarily businesses, banking and trade. Historically these sectors have been largely pro-Beijing. The last five seats are made up of district councillors who are elected by the public to sit on LegCo," read a BBC report.