The state Reapportionment Commission plans to meet Jan. 20 to begin redrawing political boundaries, following a Hawaii Supreme Court ruling last week that invalidated new maps approved by the nine-member panel in October.

The high court, in a Jan. 4 ruling, agreed with Hawaii island plaintiffs who challenged the new maps, arguing that the commission included too many nonpermanent residents — military members, their dependents and out-of-state students — in the base population count used for setting the district lines.

Including those nonpermanent residents would maintain a greater population base on Oahu and negate population gains on Hawaii island that should result in that island gaining a fourth seat in the Senate. Were they included, Oahu would lose one of its 18 Senate seats.

Plaintiffs contend that as many as 120,000 nonpermanent residents, those who live in Hawaii but claim legal residence elsewhere, should be removed from the base population number. The commission had excluded about 16,000 residents based on the ability to accurately determine their location and residency status.

Commission Chairwoman Victoria Marks has said it is doubtful that new maps would be completed by Feb. 1, the day when candidates can begin filing for elective offices. The state Office of Elections says it cannot begin accepting nominating papers until the new maps are finalized.

The Reapportionment Commission is formed every 10 years for the purpose of redrawing political districts to reflect shifts in the state’s population.