Conservative parties on Tuesday expressed unease over President Moon Jae-in's nomination of a liberal, reformist judge to lead the Supreme Court, warning it could compromise the judiciary's political neutrality.

On Monday, the liberal president tapped Kim Meong-su, the 57-year-old head of the Chuncheon District Court in Gangwon Province, to replace Chief Justice Yang Sung-tae whose six-year term ends next month.

The designation of Kim, who formerly led a group of liberal judges, caused consternation among conservatives, as some fear it could fuel the judiciary's swing to the left. Until the end of his term in May 2022, Moon can appoint 10 more justices on the top court's 14-member bench, except for Kim.

"Many point out that the nomination of Kim, the former leader of a progressive group, means the judicial establishment becoming political and ideological," Chung Woo-taik, the floor leader of the main opposition Liberty Korea Party, said during a meeting with senior party officials.

"I cannot help but express my deep concerns about a possible attempt to align the Supreme Court and Constitutional Court with (the interests of the liberal government)," he added.

The minor conservative Bareun Party also joined the criticism, raising speculations that the president could move to hold sway over the judiciary on the pretext of reform in the legal establishment.

"There appear to be both expectations and concerns over Kim's nomination," Joo Ho-young, the party whip, said during a meeting with party members.

"There are big concerns over whether the figure in sync with the president's (ideological) orientation could undermine the independence of the judiciary," he added.

The ruling Democratic Party, however, hailed Kim's nomination as a reflection of the president's strong will to reform the top court and enhance public trust towards it.

"He is a figure to bring about across-the-board reform in the judicial system that has been stuck in seniority," Woo Won-shik, the party's floor leader, said, pledging to promptly carry out the parliamentary approval process for the nominee.

"Opposition parties have to stop attempts to throw cold water on the president's resolve to conduct judicial reform," he added.

Aside from Kim, the conservative camp has continued to oppose two Constitutional Court justice nominees, taking issue with their alleged ideological bias. Amid their objections, a parliamentary vote on Constitutional Court President-designate Kim Yi-su has been delayed for months.

The chief justice nominee's appointment requires consent from a majority of lawmakers present during a floor vote that can be set up by a majority of all 299 legislators. The ruling party holds only 120 seats, making it necessary to secure opposition support. (Yonhap)