Chu Kai-pong faces a sentence of up to 10 years in jail after becoming the first convict under the strict new laws.

A Hong Kong man faces a potential sentence of up to 10 years in jail after he pleaded guilty to sedition for wearing a T-shirt featuring a protest slogan.

In court on Monday, Chu Kai-pong, 27, was the first person to be convicted under Hong Kong’s tough new national security law enacted in March.

Chu pleaded guilty to one count of “doing acts with seditious intent”. His sentencing is set for Thursday.

He was arrested on June 12 at a train station wearing a T-shirt with the slogan “Liberate Hong Kong, revolution of our times”, and a yellow mask printed with “FDNOL” – the shorthand of another pro-democracy slogan, “five demands, not one less”. June 12 is a date associated with protests in the city in 2019.

The new security law expanded the maximum sentence for sedition from two years in prison to seven years. The sentence could rise to 10 years if the defendant is found to be in “collusion with foreign forces”.

Chu’s lawyer argued that the maximum he could be given would be two years.

Following the guilty plea, Chief Magistrate Victor So announced that two other offences – failing to produce an ID card and loitering – had been dropped.

The city’s Safeguarding National Security Ordinance is the second legislation of its kind. Beijing instituted similar laws following mass pro-democracy protests in 2019.

It grants the government more power to quash dissent, widely seen as the latest step in a sweeping political crackdown.

The offence of sedition was created under British colonial rule, but was seldom used until the authorities revived it in 2020.

The new security law, which punishes five categories of crime – treason, insurrection, sabotage, espionage and external interference – expanded the offence to include inciting hatred against China’s communist leadership.

The International Bar Association has denounced the new law, saying the “vague definitions of the crimes … allow opportunity for arbitrary and politically motivated prosecutions”.

As of August, 301 people had been arrested under the two security laws, with 176 prosecuted and 157 convicted, including two former editors of the now-defunct Stand News.