South Korea's progressive umbrella union on Tuesday announced it will withdraw support for the minor Unified Progressive Party (UPP), citing failure of the party to push forward meaningful reforms.

The decision by the Korea Confederation of Trade Unions (KCTU) made in an 11 hour-long marathon discussion session, comes after the UPP failed last month to pass a motion expelling Reps. Lee Seok-ki and Kim Jae-yeon, who have been accused of unfairly winning proportional representative seats in the April 11 parliamentary elections.

Lee, a leader of the so-called pro-North Korea faction within the party, also sparked a nationwide uproar when he said South Korea does not have an official national anthem.

The failure to deal with the controversial pro-North Korea faction and its alleged election rigging has fueled a fierce feud within the left-leaning party with reformist members who make up the minority threatening to leave and create their own political entity.

There has also been a rise in the number of members leaving the party as well as a weakening of public support, but UPP loyalists claimed moves to set up a new political entity could break up the progressive camp ahead of the critical Dec. 19 presidential election.

The KCTU, meanwhile, said its decision to break up with the UPP was reached with 27 of the 39 representatives voting in support of the move during a closed-door central executive committee meeting.

The KCTU action is expected to impact the UPP, since the union is the single largest support base for the party and had consistently tried to push it to reform itself to meet the expectations of the general public. Of the UPP's 75,000 members with voting rights, 46 percent or nearly 35,000 are part of the large umbrella union.

Before the latest action, the labor union issued an ultimatum in May calling on the UPP to take all necessary steps to reform itself and deal with the election fraud issue. At the time, the trade union called for the wholesale resignation of proportional candidates who were elected, the party leadership and secretariat.

"The decision to withdraw support was based on an independent assessment of the situation by the union," the KCTU said in a press release.

Jung Ho-hee, a spokesperson for the union, said the latest measure does not automatically translate into the KCTU supporting the creation of another progressive party.

The union official said there has been no contact with UPP reformists asking for the union's aid.

In addition to withdrawing support, the union organization's central committee reaffirmed its plan to conduct a nationwide strike this month and stage a protest by its members in Seoul on Aug. 31.

The KCTU demanded an end to hiring irregular workers with weak job protection, a halt to the practice of allowing companies to lay off employees when they are in trouble and a revamping of the country's union laws. (Yonhap News)