CORBIN — FRANKFORT, Ky. (AP) — Legislative candidates will have to run in decade-old districts in this year’s elections, the Kentucky Supreme Court ruled Friday afternoon.

Chief Justice John D. Minton, writing for the full court, said newly drawn legislative districts are “facially unconstitutional” and that lawmakers will have to operate under the old districts until more balanced boundaries are drawn.

Justices heard oral arguments Friday morning in the redistricting case that has been speeding through the legal process. The original lawsuit was filed only a month ago.

Franklin County Circuit Judge Phillip Shepherd ruled earlier this month that newly drawn legislative districts are out of balance and must be redrawn to comply with the “one person, one vote” mandate in federal and state law. Challenges were quickly taken to the Kentucky Court of Appeals and then to the Supreme Court.

The Supreme Court upheld Shepherd’s ruling. Justice Will T. Scott had recused himself from the case because he is seeking re-election this year in a judicial district that was redrawn under the same legislation that reshaped legislative districts.

“This is really an easy case,” Lexington attorney Scott White said in brief comments to the Supreme Court earlier Friday. White is representing Democratic state Sen. Kathy Stein, whose district was shifted more than 100 miles northeast from Lexington. He said justices simply had to decide whether lawmakers could have created a better population balance between legislative districts.

Besides being shifted geographically, Stein was being ushered out of the Senate at the end of this year under the redistricting plan. She praised the Supreme Court ruling as “magnificent.”

“It was clear what was happening,” said Stein, a liberal Democrat in a Senate controlled by conservative Republicans. “I know it was political, but it just didn’t make sense.”

Justices also upheld the Feb. 10 filing deadline for legislative candidates. And Secretary of State Allison Lundergan Grimes said Friday she intends to certify legislative candidates on Monday so that county elections officials can begin preparing ballots for the May primary.

Redistricting occurs every 10 years to account for population changes reported in the U.S. Census. The latest count found that the state’s overall population grew from 4 million to 4.3 million between 2000 and 2010, requiring new legislative and congressional district boundaries. At each level of government — state House, Senate and Congress — the districts must be of nearly equal size.

Unhappy with the outcome of legislative redistricting, House Republicans sued in late January. Stein joined the lawsuit, which contends that the new districts are unconstitutional.

The changes produced some oddly shaped legislative districts. One House district stretched from the Tennessee line in McCreary County, zigzagged narrowly through Laurel County, then encompassed all of Jackson County. One Senate district stretched more than 130 miles from Barbourville to Morehead.

Kentucky is one of at least 25 states with pending court cases involving redistricting. A similar Kentucky lawsuit filed after the 1990 Census established some of the case law that House Republicans reference in their challenge.

Senate President David L. Williams said in a statement Friday that he’s ready to work on new legislative districts.

“The Supreme Court has the ultimate authority to determine the constitutionality of any statute and I accept their decision,” he said. “We stand prepared to run in the old districts or draw new legislative lines, if the House is so inclined, in conformity with the Supreme Court ruling.”

Meanwhile, some are pointing to the divisive redistricting process as reason to enlist an independent commission to handle the chore.

“This year’s debacle over redistricting is part of a recurring trend,” said Jim Waters, head of the conservative Bluegrass Institute for Public Policy Solutions in Bowling Green. “The system is broken to the point that the constitutional guarantees that all citizens will be properly represented are being threatened. While the Legislature still must oversee the process, an independent commission needs to draw the lines.”