Upholding a lower court ruling, a Seoul high court on Friday recognized the status of a progressive teachers' union as a legal trade union, pending its decision on the status.

In October, the government outlawed the Korean Teachers and Education Workers Union (KTU) due to its repeated refusal to deny membership to fired teachers. In a landmark ruling in June, the Seoul Administrative Court approved the decision, depriving the KTU of its 14-year-old status as a legal trade union.

Despite the government's decision, the union had maintained its legal status until the June ruling was made as it won an injunction from the same court against the government's move in November.

On Friday, the Seoul High Court upheld the injunction, ruling that the union's legal status should remain intact until its judge decides on the matter.

The court also accepted a request from the union that the Constitutional Court review whether the law governing the status of teachers' unions based on which the labor ministry outlawed the KTU goes against the Constitution.

Article No. 2 of the law prevents dismissed teachers from being members of their trade union.

"The article possibly goes against the principle of excessive prohibition ensured under the Constitution and infringes upon teachers' rights to organization and equality," Judge Min Joon-gi of the court said.

The 60,000-strong KTU has as members dozens of teachers who were sacked for signing statements against the former Lee Myung-bak government in 2009.

If the Seoul Administrative Court decision denying its legal status is confirmed by the top court, the union would be prohibited from using the title "labor union" and engaging in legitimate negotiations with school authorities. The union's 78-member full-time staff members should also return to teaching jobs at school.

The appellate court's injunction is expected to deal a blow to the education ministry, which has already taken steps to follow up on the union's change of status since the lower court injunction lost its effect with the June court ruling.

Nearly 50 union executives have returned to teaching jobs as the ministry threatened to fire them otherwise. The ministry is now taking steps to fire some 30 others who refused to return.

"We're discussing how to deal with the latest court decision," a ministry official said, requesting not to be named.   

Founded in 1998, the progressive teachers' union became a legitimate organization the following year under the liberal government led by President Kim Dae-jung and has grown into the country's second-largest teachers' union. (Yonhap)