The Unified Progressive Party is facing its biggest crisis ever following revelations of vote-rigging and other irregularities in its candidate selection process, which it once touted as an example of grassroots democracy.

With rival factions still fighting and a prosecutorial probe looming, leaders of the far-left minority party on Thursday offered a public apology.

“Whatever the reason, or the circumstance may have been, we have let voters down,” Lee Jung-hee, one of the party’s four co-chairs, said during a party meeting at the National Assembly in Seoul.

“I will assume political and moral responsibility for it” she said. 

The other co-chairs ― Rhyu Shi-min, Sim Sang-jeong and Cho Jun-ho ― made similar remarks.

On Wednesday, the UPP had announced results of an internal investigation into claims of irregularities in an intra-party election in March to select proportional representative candidates.

Co-leader Cho, who had led the in-house probe team, said that the problems found in the primary process were so grave that the whole process and its results lost legitimacy and credibility.

The announcement left the UPP in tatters, just as it prepares to join the new parliament with a strengthened clout as the third-largest party. It won 13 seats, including six through proportional representation, of the new 300-member parliament in the April 11 general election.

Seoul Central District Prosecutors’ Office said Thursday that it is launching an investigation, following a complaint filed by a far-right civic group.

UPP leaders opposed the move, insisting that they will fix their problems on their own. They decided to release to the public the report from the in-house investigative team.

Political observers said the irregularities could chip away at the progressive force’s core political asset ― a public image of higher standards and adherence to democratic principles. Many UPP politicians were pro-democracy fighters under military regimes and labor activists.

Professor Cho Kuk of Seoul National University, a leading progressive voice in academia, said he was at a loss for words at the way leftist politicians abandoned the procedural democracy for their factional interests.

“Party leaders should resign and let outside figures form an emergency leadership committee and pull the party together,” he said.

The UPP was created last December by the merger of three groups: Democratic Labor Party led by Lee, People’s Participation Party led by Rhyu and a group of defectors from the New Progressive Party led by Sim. Lee, Rhyu and Sim now co-chair the UPP, along with Cho.

The power struggle between the two larger of the three ― the DLP and PPP ― seems to have led to vote-rigging attempts, political observers said.

The top three spots on the party’s list of proportional candidates went to DLP members.

The UPP held a primary to elect proportional candidates from March 14-18. Members cast their ballots in three ways: in person at a polling station, via the party’s website or through their cell phones.

Vote-rigging is suspected in its on-the-scene and online voting.

By Lee Sun-young (milaya@heraldcorp.com)