The main opposition Democratic Party has rejected President Lee Myung-bak’s proposal that he would seek renegotiation with Washington on a contentious clause in the Korea-U.S. free trade agreement if the DP cooperates in ratifying the trade pact.

Lee made the offer at a meeting with leaders of the ruling Grand National Party and the DP on Tuesday. He made a rare visit to the National Assembly to break the impasse over the ratification of the KORUS FTA.

He was quoted as saying that “if the Assembly ratifies the trade deal and recommends that the Seoul and Washington governments renegotiate on the disputed investor-state dispute provision, I will ask the U.S. for renegotiation within three months after the deal goes into effect.”

Yet DP lawmakers turned down Lee’s offer and decided to stick to their line of “renegotiation on ISD first and ratification later.”

Saying that Lee’s oral promise was not sufficient, the lawmakers demanded a written agreement made between ministerial-level officials of the two countries with a promise to renegotiate the ISD clause immediately.

Their decision poured cold water on the efforts of Lee and the ruling Grand National Party to elicit the opposition party’s cooperation in ratifying the trade deal.

DP lawmakers held a lengthy debate on Lee’s offer yesterday. But DP leader Sohn Hak-kyu set the tone for the debate by calling for an outright abolition of the ISD clause, a demand that went one step further than his previous call for renegotiations on it.

Yet the DP’s stance is difficult to understand. Following Lee’s proposal, Washington expressed willingness to discuss the controversial ISD issue with Seoul once the KORUS FTA takes effect. This can be seen as firm U.S. support for Lee’s new proposal.

Washington noted that the two countries recently agreed to establish the KORUS Committee on Services and Investment to deal with any specific issues, including ISD, that might arise after the agreement goes into effect.

Nevertheless, DP leader Sohn buried his head in the sand, ignoring Washington’s flexibility. His maximalist strategy deserves criticism because it puts partisan interest before national interest.

The DP leader overstepped his bounds in dealing with the FTA issue. He was blinded by a desire to win the support of the Democratic Labor Party in next year’s parliamentary and presidential elections.

Sohn’s unreasonable intransigence triggered a backlash from the party’s moderate lawmakers, who called for a secret vote on their compromise proposal to change the party’s stance. Yet the party’s leaders ignored their demand.

Sohn and other DP leaders should realize that a delay in the parliamentary ratification of the trade deal could inflict a huge economic cost on Korea. According to one estimate, a one-year delay in the ratification of the pact could incur economic losses worth 15 trillion won.

This is because U.S. President Barak Obama is pushing for the Trans-Pacific Partnership, a free trade agreement with a dozen or so Pacific-rim countries. This project got a big boost Friday when Japanese Prime Minister Yoshihiko Noda announced that Tokyo would join negotiations on it. Canada and Mexico also expressed interest in joining the deal.

During the annual summit of the Asia-Pacific Economic Cooperation forum in Honolulu last weekend, Obama held talks with the participating countries and said TPP could be finalized next year as scheduled.

If the scheme goes as planned, it would create a regional economic group 40 percent larger than the 27-nation European Union. It is plain as day that Korea stands to lose its edge in the free trade accords if Japan participates in the TPP.

Hence, it is incumbent that the political parties ratify the KORUS FTA without any further delay and ensure that it goes into effect in January.

For the ruling party, the time for action has come. President Lee has done what he could. He promised on his honor that he would have Washington accept Seoul’s demand for renegotiation on the ISD provision. The DP’s rejection of Lee’s final offer means it has no intention to handle the FTA issue through dialogue. In that case, the GNP has no other choice but to take action.