The state Legislative Reapportionment Commission’s recently approved House and Senate districts are contrary to Pennsylvania law, the state Supreme Court has narrowly decided, remanding the redistricting effort to the commission in an unprecedented move.

The existing districts from a 2001 plan, which the court then approved and have been in place for the last decade, will remain in effect until a revised plan “having the force of law” is approved, the 4-3 court said in a per curiam order. The court did not impose a time frame for the commission, which approved its plan 4-1 in December, to present a new set of districts. The high court retained jurisdiction and said an opinion explaining its decision would follow.