The Supreme Court's First Petty Bench decided Wednesday to have the top court's Grand Bench issue a unified ruling on five damages lawsuits filed by forced sterilization victims under the now-defunct eugenic protection law.

The Grand Bench, presided over by Chief Justice Saburo Tokura, is expected to hand down such a ruling next year on the suits, with the top court's judgment on whether the 20-year statute of limitations for damages claims applies in the cases expected to be a focal point.

The lawsuits were initially filed with district courts in Sapporo, Sendai, Tokyo, Osaka and Kobe. All but Tokyo District Court found the old law unconstitutional, while all the five rejected damages claims citing the statute of limitations.