A progressive teachers' union said Monday it may stage a walk-out next month to protest the government's plan to lower pensions for civil servants, including public school teachers.

The Korean Teachers and Educational Workers' Union said its members will take a vote at the end of this month to decide whether to take a paid leave and go on strike on April 24.

If the strike occurs, it would the first one in nine years in which the KTU members have taken paid time off to strike.

The announcement comes after the ruling Saenuri Party revealed a draft bill late last year that would start requiring public workers to pay more into the pension system and receive less pension from 2016.

The bill is part of a government plan to cut its growing pension deficit, which is forecast to reach 484 trillion won ($458 billion) if left unaddressed.

Government workers, however, have rejected the proposal, saying they have tolerated low pay for the promise of high returns after retirement.

The union was outlawed for a few months last year after a Seoul court approved the government's decision to strip the union of its legal trade union status because it had refused to deny membership to fired teachers.

In September, however, the Seoul High Court upheld an injunction ordered by a lower court and ruled that the union's legal status should remain intact until the top court decides on the matter. (Yonhap)