The leader of South Korea's largest opposition party has rejected the central government's proposal for settling the wartime labor issue with Japan.

Democratic Party leader Lee Jae-myung explained his criticism of the proposal at a meeting on Monday.

The government last week floated the idea of using a public foundation to pay the plaintiffs in wartime labor lawsuits in place of Japanese companies that have been ordered to pay damages by South Korea's Supreme Court.

Lee said the proposal would allow Japan to justify its war crimes and shift the responsibility onto South Korean businesses.

He faulted the 2015 agreement between South Korea and Japan that confirmed that the issue of those referred to as wartime comfort women was resolved finally and irreversibly.

He said it was too hastily arranged, and added that Seoul needs to learn lessons from it when facing the wartime labor issue.

The opposition leader urged the government to immediately stop what he called a diplomacy of self-flagellation.

A legal expert attending the meeting stated that the plaintiffs would have to give their consent to allow a foundation to pay in place of Japanese companies.

The South Korean government is looking for a breakthrough to improve ties between the two countries. It plans to draw up a measure to resolve the issue at an early date based on the proposal.

But Lee's remarks made it clear that the government's stance differs greatly from that of the plaintiffs and the main opposition party.