Japanese citizens will examine serious criminal cases such as murder with professional judges under the new system, but critics have questioned such issues as what they describe as excessive penalties imposed on the lay judges if they breach confidentiality.

The lawmakers who are to join the move to present the bill are expected to be from the ruling Liberal Democratic Party, the main opposition Democratic Party of Japan and two other tiny opposition parties -- the Social Democratic Party and the People's New Party.

The law, enacted in 2004, sets a maximum penalty of six months in prison or 500,000 yen in fines for lay judges who fail to observe confidentiality. The duty of confidentiality will also continue even after a person is no longer a lay judge.

The lawmakers plan to submit a revised lay judge law, which would likely stipulate that "the time of enforcement will be postponed until a day separately designated in a law," the group members said.

Hisaoki Kamei, a PNP lawmaker representing the group, stressed that it is only the legislative body that can stop the system as concerns grow among the public.

"Even if the bill does not pass the Diet, I believe we can create a stir (by presenting the bill)," he told a press conference after the group held a meeting in Tokyo.