A court upheld Thursday the government decision to deprive the Korean Teachers and Education Workers' Union (KTU) of its legal status as a trade union.
As a result of the ruling by the Seoul Administrative Court, the progressive teachers' union loses its legal rights for collective negotiations and may not keep full-time members who are paid by schools.
The 60,000-member KTU has 78 full-time paid members.
Right after the court's verdict, the KTU held a press conference and said it will appeal the ruling while filing for an injunction against the decision.
"We will now actively try to amend the current Teachers' Union Law, which we think is discriminatory against teachers," said the union.
In October, the Ministry of Employment and Labor stripped the organization of its legal status after it repeatedly refused to follow a government order to deny membership to fired teachers.
The KTU voted in October on whether or not to comply with the order; and decided not to. The labor ministry then said that it would no longer consider the KTU a labor union as it had violated the law.
The KTU filed a suit against that decision.
The teachers' group and the government had already fought a similar case in court.
In 2010, the ministry said that the KTU was violating the Teachers' Union Law and asked it to correct this. The KTU requested the court to rule against the order, but lost in the Supreme Court.
"The nine dismissed teachers who are now members of the KTU were not fired unfairly. They were either found guilty in criminal trials or lost in suits against their dismissals, so they cannot be union members," said the three-judge panel led by Ban Jung-woo.
Under both the trade union and teachers' union laws, a fired employee can appeal against dismissal to the National Labor Relations Commission and remain a union member until the authority's decision.
In the case of umbrella unions, those who are temporarily jobless and are looking for work can remain as members.
The Seoul Administrative Court said that such standards should be stricter for teachers because they are different from ordinary employees and should have "ethicality, independence, impartiality, public character and professionalism" in their role of educating students.
The KTU was set up in 1989 during the Roh Tae-woo administration. Some 1,500 members were fired for taking part, and 1,300 of them were reinstated in 1994.
When the law on establishing teachers' labor unions passed the National Assembly in 1999, the KTU also earned its legal status.