Dozens of Hong Kong’s most prominent pro-democracy figures have been jailed – one for 10 years – in the territory’s largest national security trial, after a prosecution that has been widely criticised as politically motivated.

Those jailed are among 47 people, known as the “Hong Kong 47”, who were charged in 2021 under the punitive national security law (NSL) with conspiracy to commit subversion over their involvement in pre-election primaries held in 2020 before the Hong Kong general election. Most have already spent more than three years in jail, but none were released on Tuesday.

Of the 47, 31 pleaded guilty, and two were acquitted at trial. The 14 who were convicted after pleading not guilty were given harsher sentences.

Gordon Ng, an Australian-Hong Kong dual national, was sentenced to seven years and three months.

After the sentencing, Australia’s foreign minister, Penny Wong, said Australia was “gravely concerned” about Ng’s sentence, and had expressed its “strong objections to the Chinese and Hong Kong authorities on the continuing broad application of national security legislation”.