The ruling and opposition parties clashed Thursday over a presidential office request to renegotiate the appointment of two special counsel candidates tasked with re-investigating allegations of state funds being misused to buy land for President Lee Myung-bak's retirement home.

The presidential office Cheong Wa Dae urged political parties to follow the letter of a pact on the appointment of candidates for the special prosecutor post, hinting it viewed the two proposed lawyers as being pro-opposition and unlikely to carry out a fair investigation.

This move came a day after the Democratic United Party (DUP) on Tuesday recommended former judge Lee Kwang-bum and civil rights lawyer Kim Hyoung-tae as candidates for the special counsel post.

Lee is a member of the progressive Society for Research on Our Law and Kim a member of Lawyers for a Democratic Society. Both organizations have been at odds with the incumbent administration.

The DUP, however, said the president is obliged by law to pick one of the two candidates by Friday.

"If the president does not pick either Lee or Kim, he will be breaking the law, since parliament passed the special prosecutor law and the chief executive did not veto it when he had the legal right to do so," the party said in a press release.

Echoing this view, DUP floor leader Park Jie-won said in a radio talk show earlier in the day that under the pact reached in August, the opposition was given the sole right to recommend two candidates.

Saenuri Party's senior officials declared the DUP broke the agreement by moving forward on the unilateral appointments, and called for re-negotiations.

Floor leader Lee Hahn-koo claimed the two lawyers were tapped without due consultation. That, he said, was a clear breach of faith.

"The move can only be viewed as a ploy to use the special prosecutor to gain an upper hand in the Dec. 19 poll," he claimed.

Lee said the DUP must apologize to the public for corrupting the investigation into an election strategy.

Party sources expressed concerns a pro-opposition counsel could raise unfounded suspicions about the deal and hurt the ruling camp's presidential candidate Park Geun-hye's bid in a very tight race.

The controversy centers around a deal to buy a plot of land in Naegok-dong on the southern edge of Seoul for a retirement home for Lee, and auxiliary facilities for security personnel. The land was bought jointly by Lee's 34-year-old son, Si-hyung, and the presidential security service.

The cost was not shared evenly, however, with the security service paying a higher price for the site to build its facilities.

This move, the opposition argued, was a scheme to allow the son to profit from buying the site at a below-market price.

The presidential office has flatly rejected such claims and said Si-hyung only took part in the deal for security reasons. The president later scrapped the project altogether and decided to move into his existing private house in Nonhyun-dong in southern Seoul when he leaves office.

State prosecutors had launched an investigation into the matter but closed the case, saying they found no sign of irregularities.

Political pundits, meanwhile, said because neither Saenuri nor the DUP are willing to back down from their respective stances, the president may opt not to pick either candidate by the legal deadline.

Such a development, they said, could rock the political establishment and trigger fresh wrangling by parties and debate on the legality of the chief executive's actions. (Yonhap News)