The progressive Korea Teachers and Education Workers' Union (KTU) is facing an uncertain future as education authorities are moving to dismiss more than 100 of its unionized teachers.
The planned dismissal will be the largest ever since the union's establishment in 1989, and has sparked a strong protest from the union.
The Ministry of Education, Science and Technology announced Sunday it was moving to sack 134 public school teachers, who reportedly signed up for the membership of the minor opposition Democratic Labor Party, and suspend four others.
"Teachers are bound to maintain their political neutrality. Paying membership fees to support a certain political party is illegal," the ministry said.
Of those fired, 50 ― who publicly denounced the government last year ― will be dismissed without benefits, depriving them of pensions and other perks given to civil servants.
The dismissal process is expected to take about 60 days.
The action comes following prosecution indictments of 148 teachers at public and 35 from private schools for joining the progressive political party earlier this year.
The KTU leader, Chung Jin-hwo, labeled the incident as a "Bloody Sunday" and said the union will join hands with liberal civic groups to pressure the government to reverse the decision.
Some leaders have already started a hunger strike in front of the ministry building in central Seoul, and are planning anti-government demonstrations during the June 2 local election campaign period.
"We have explained to the government several times that the money handed to the DLP was a donation, not a membership fee. Moreover, being interested in political issues should not be grounds for dismissal," Chung said in a press conference in Seoul.
"Punishing the members before a court ruling is ridiculous. They are holding a witch-hunt before the local elections," said Yang Sung-yoon, head of the Korean Government Employees' Union.
The KTU has been at odds with the conservative administration over state-run standardized exams for elementary and secondary school students, and teacher evaluation programs.
Recently, Rep. Cho Jeon-hyeok of the ruling Grand National Party disclosed a list of its members on his Web site, citing parents' right to know the political affiliation of their children's teachers. A court banned this for violating the teachers' privacy and ordered him to pay 30 million won in fines for each day the names were left posted on his site.