Missouri Attorney General Catherine Hanaway and Secretary of State Denny Hoskins asked the U.S. Supreme Court Friday to allow the state to use a new congressional map in the November midterm elections, challenging a ruling by the Missouri Supreme Court that restored the previous district boundaries.

The Republican-backed map was adopted by the Missouri Legislature in 2025 and was used during the state’s August congressional primaries. The new boundaries were designed to strengthen Republican prospects for an additional U.S. House seat and included significant changes to the Kansas City-based district represented by Democratic Rep. Emanuel Cleaver.

The Missouri Supreme Court unanimously ruled Thursday that the new map could not be used in the November general election unless it is approved by voters through a statewide referendum. The court determined that a referendum petition containing more than 300,000 signatures was valid and that the previous congressional map, adopted following the 2020 census, remains in effect for the November election.

The ruling came after Hoskins had rejected the referendum petition, arguing that Missouri's Constitution did not permit voters to use the referendum process to challenge congressional redistricting. A lower court had upheld his decision before the Missouri Supreme Court reversed it.

Hanaway is asking the U.S. Supreme Court to immediately halt the state court's ruling. In the emergency filing, she argued that changing the congressional boundaries after the primary election could create significant logistical problems for election officials, candidates and voters. The state has also warned that it could face difficulties meeting federal deadlines for sending ballots to military and overseas voters.

Justice Brett Kavanaugh, who handles emergency matters from the region, directed opponents of Missouri's request to respond by Monday. Missouri faces a Tuesday deadline for making changes to the November ballot.

Missouri currently has six Republicans and two Democrats in the U.S. House. The dispute is part of a broader mid-decade redistricting fight that has spread across multiple states ahead of the 2026 elections.

The statewide referendum on the new congressional map is scheduled to appear on the November ballot, while the Supreme Court considers Missouri's request to restore the map for this year's general election.