When Lee Yong-deuk, leader of the more moderate of Korea’s two national labor unions, joined the main opposition Democratic United Party as an appointed member of its executive council last year, he must have had specific goals to attain other than simple policy coordination. Observers guessed he must have been aiming at securing “several” National Assembly seats for his colleagues at the Federation of Korean Trade Unions, if not for himself, in the forthcoming general elections.

Last week, Lee threatened to leave the party, complaining that the party had completely ignored the union in the ongoing nomination process for the April 11 polls. News reports revealed that the DUP leadership and the nomination committee rejected Lee’s demands that unionists be chosen for 3 to 4 districts and at least two slots in the proportional representation list.

It is not hard to imagine how the internal negotiations went on over the past few weeks. DUP headquarters is in near chaos these days with wild protests by aspiring candidates who were dropped in the screening. Party leaders, meanwhile, are deeply troubled by the unexpected complications of the “mobile nomination” procedures, which revealed the serious drawback of proxy registration. A party cadre committed suicide last week while being investigated for gathering favorable voters for a district primary.

Internal strife is getting fiercer in the DUP with every passing day as the Honam faction made up of the old guard loyal to the late President Kim Dae-jung is trying to prevent the “Roh Moo-hyun loyalists” from dominating the party, particularly in the nomination process. In this shaky situation, neither party chairwoman Han Myeong-sook nor any of the other leaders can entertain the wishes of the unionists.

Lee Yong-deuk was deeply embarrassed when the Chosun Ilbo published what it called a “provisional list” of the DUP’s proportional representation candidates, in which he was ranked second among 20-odd names. He denied the authenticity of the list, asserting that he never sought an Assembly seat for himself. Lee Suk-hyung, a former leader of the radical Minjunochong or the Korea Confederation of Trade Unions, was also included on the list.

It is the first time in the 66-year history of the FKTU that its chief has been an executive member of the opposition party. During the 2007 presidential race, Lee Yong-deuk brought his union into a “policy alliance” with the then main opposition Grand National Party and supported its candidate Lee Myung-bak. That alliance continued after President Lee’s election but was broken after no FKTU representative was included in the GNP’s proportional representation list in the April 2008 election.

The politicization of labor unions is inevitable and it is perfectly normal for a union to endorse a candidate in an election. Yet, shifting from one party to another with completely different ideological orientation needs a justifiable motivation that can convince rank and file members. If the FKTU had supported Lee Myung-bak’s business-friendly platform in 2007, the union leadership should now be able to explain what merits the DUP has to deserve its support.

Within the FKTU, criticism has mounted from among affiliate unions since Lee joined the DUP executive council. A national convention of union representatives scheduled for late February was postponed as more than half of the delegates abstained from it, complaining that the FKTU was becoming a political arm of the DUP ― presumably lured by the chance of getting a few lawmakers’ badges.

If Lee Yong-deuk and his colleagues chose the DUP because of a strong prospect of its winning in the elections this year, they need to look back on the consequences of the union’s political gamble five years ago. Friendship between a union and a government, whether from the right or left, cannot but be fragile. Now, the situation is even more complicated as the DUP is seeking to ally with other left-wing groups including the United Progressive Party, which is supported by Minjunochong, a radical rival of the FKTU.

Lee said that the DUP has abandoned the spirit of “togetherness with the labor and civil society forces” and exposed the problems of “elite politics, closed-door nominations and privileges of the incumbent.” If his observations are correct, there is no reason why he should remain in the party. His only choice is to make good on his ultimatum.