South Korea's teachers union on Sunday rejected the labor ministry's ultimatum that called for a rewriting of its bylaws that would prevent fired educators from staying on as members.

The moves comes as Seoul said last week that the union must make changes to its rules and warned that failure to do so would result in the Korean Teachers and Education Workers Union (KTU) losing its rights as a formal labor union that can engage in legitimate negotiations with schools. Under current labor law only employees of a workplace are qualified to become union members.

In a meeting of its national representatives held in Daejeon 160 kilometers south of Seoul, KTU said it will not make the changes because it violates the independence of the organization to pick its members.

"The decision has been made to reject the government's demand with representatives agreeing to take steps to fight against the government," the union said.

A spokesperson for teachers said that depending on what future actions are taken by the government, members will engage in strikes, hold candlelight vigils and carry out other measures to show the public the "unlawfulness" of the government's actions. He said that more effort will be taken to reinstate fired teachers into the union.

The teachers union has already come under flak from numerous parents for teaching pro-North Korean views such as calling for the expulsion of U.S. forces from the Korean Peninsula.

The labor ministry said if the union insists on maintaining its unlawful practice it will be re-classified as an outsider or an unregistered union.

The union, meanwhile, said that it would work closely with the Korean Government Employees' Union (KGEU) to come up with a concerted plan against the government's latest crackdown. The KGEU is an outsider union made up of lower ranked government employees. (Yonhap News)