South Korea’s Supreme Court confirmed Wednesday a three-year jail sentence for Han Sang-gyun, the leader of the nation’s second-biggest umbrella labor union, for leading violent rallies. Labor groups denounced the ruling as a regression of democracy.

Han, head of the Korean Confederation of Trade Unions, was convicted on charges of leading a series of illegal rallies at the end of 2015 and causing damage to public property and police officers.

Violent clashes erupted at some of the rallies, which were organized to protest then-President Park Geun-hye’s controversial labor and education policies.

The lowest court sentenced him to five years in jail, saying he did not take any measures to stop clashes between demonstrators and the police. The high court reduced the term to three years, saying the police’s response was somewhat excessive.

The KCTU and human rights organizations blasted the ruling, asking the Moon administration to pardon him.

“It was a humiliating ruling that justified the police’s installment of bus barricades and use of water cannons to crack down on public assemblies and resistance against illegal power,” the umbrella labor union said in a statement.

Amnesty International said that no one should be behind bars for exercising basic human rights to freedom of expression and peaceful assembly.

“Today’s ruling is a further setback for justice and human rights in South Korea,” said Nicholas Bequelin, East Asia regional director at Amnesty International. “President Moon Jae-in should demonstrate that the new government fully supports the right to peaceful assembly and stop these unjust prosecutions.”

Sharan Burrow, general-secretary for the International Trade Union Confederation, said Han should not be jailed for leading working people’s fight for justice.

“Union leaders who stand with working people and civil society, they are seen as heroes in other countries. They are not put in jail,” Burrow said in a press briefing Tuesday.

The decision comes after the police said they would not dispatch police forces, water cannons and bus barricades at street rallies anymore in line with the Moon administration’s pledge to better protect citizens’ civic rights.

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)