Three young Hong Kong activists, including Joshua Wong, are making a last-ditch attempt to overturn prison sentences for their roles in sparking 2014’s massive pro-democracy protests in the semiautonomous Chinese city.

Lawyers for the three were presenting arguments Tuesday in an appeal hearing at Hong Kong’s top court.

Wong, Nathan Law and Alex Chow were initially let off with suspended or community service sentences after they were convicted of taking part in or inciting an unlawful assembly.

But the case sparked controversy when the justice secretary requested a sentencing review that resulted in stiffer sentences, raising concerns about rule of law and the independence of Hong Kong’s judiciary.

The case underscores wider tensions over Hong Kong’s increasingly tense relationship with China’s communist leaders in Beijing.

“I hope that for today’s verdict the Court of Final Appeal really treasures the motive of people fighting for democracy and fighting for justice as part of the consideration when making any judgments,” said Law, 24, who was elected Hong Kong’s youngest lawmaker following the protests but then disqualified from office in a government legal challenge.

Wong, speaking on the courthouse steps, estimated he had a 50-50 chance of going back to prison. “However I still believe that when people are united we will not be defeated.”

The 21-year-old Wong made world headlines and starred in a Netflix documentary after leading the “Umbrella Movement” protests while still a teenager. The protests, which brought parts of the busy Asian financial hub to a halt over Beijing’s plan to restrict elections for top leader, ended without resolution after 11 weeks.

The three were given revised sentences ranging from six to eight months of prison time in last year’s ruling, which said there was a need for deterrent after they committed serious offenses by storming a courtyard at government headquarters to kick of the protest movement in September 2014.

The trio served two months and then were released on bail when they won permission to appeal. They could be sent back to prison immediately if the judges reject their case.

Their legal teams are expected to seek clarification on how much the court should take into account the motive of civil disobedience over the need for deterrence when sentencing protesters.

Wong could end up back in prison anyway. He is due to be sentenced in a separate court case on Wednesday involving contempt charges also related to the 2014 protests.