A Hong Kong man has been sentenced to 14 months in prison after pleading guilty to sedition for wearing a T-shirt emblazoned with a protest slogan. This is the first case of its kind under a new local law passed in March,

Chu Kai-pong faces up to 10 years in prison under the new security law. Critics have argued that the term sedition has been vaguely defined, and it could be used to curb dissent.

Activists hold flags that read 'Free Hong Kong, Revolution Now': The Hong Kong government increased the maximum sentence for sedition to seven years but it can be raised to 10 if the defendant is found to be in collusion with foreign forces. Photograph: Sam Yeh/AFP

A Hong Kong man convicted for wearing a "seditious" T-shirt last year was sentenced to 14 months in jail under the city's new security law that continues to crack down on supporters of anti-government demonstrations.

A Hong Kong court sentenced a man to 14 months in prison for wearing a T-shirt with protest slogans, marking the city’s first use of a new national security law to punish people accused of endangering the Chinese state.

Critics feared the law could further erode civil liberties in the city, while Beijing and Hong Kong defended it, saying it was necessary for stability. Chu Kai-pong, 27, was arrested at a subway station in June wearing a T-shirt sporting the phrase "Liberate Hong Kong,