A Hong Kong court has jailed a man for 14 years for his role in an “evil” bomb plot against the authorities during and after the 2019 anti-government protests.

The High Court on Thursday convicted Cheung Lai-ming of four charges after he pleaded guilty to making explosives at his public rental flat in Wong Tai Sin, with a view to carrying out attacks between August 2019 and May 2022.

The 35-year-old programmer also admitted keeping more than 20kg (44lbs) of chemicals capable of making explosives at his home and in a storage room in San Po Kong.

Cheung, a University of Hong Kong graduate, was initially due to stand trial under the Beijing-imposed national security law for allegedly conspiring with others to commit terrorist acts.

Prosecutors agreed not to pursue the terrorism charge on condition that he pleaded guilty to the remaining four counts under the colonial-era Crimes Ordinance: conspiracy to cause explosions likely to endanger life or property, attempting to make an explosive substance, and two counts of possessing explosive substances.

Mr Justice Andrew Chan Hing-wai said Cheung and his co-conspirators intended to plunge the city into “maximum chaos”, disrupt public order and undermine the stability of Hong Kong’s political system by targeting government officials, police officers and judges.