A federal judge in Missouri on Tuesday temporarily halted the state's use of its old congressional districts for the November election, following the U.S. Supreme Court's decision not to intervene in the intricate and confusing legal dispute.

The rulings underscore the convoluted nature of Missouri’s redistricting dispute, which has persisted for over a year.

The federal court action came just days after the Missouri Supreme Court ruled that the state cannot implement a new U.S. House map endorsed by President Donald Trump for the November election, given that citizens had submitted thousands of petition signatures demanding a statewide referendum on the matter.

The U.S. Supreme Court on Tuesday declined to review an appeal from Missouri's Republican attorney general, thereby upholding the injunction issued by the state's highest court.

Yet moments later, U.S. District Judge Stephen Clark issued a temporary restraining order that barred Missouri from using any district maps other than the newly drawn ones favored by Republicans.

The newly drawn districts were utilized in the August primary, and the victorious candidates have already received certification from election officials.

The uncertainty over which district boundaries will apply to the November election remains unresolved.

This is a breaking news update; AP's earlier report is provided below.

The Supreme Court on Tuesday rejected an appeal from Missouri officials who sought to implement new congressional districts backed by President Donald Trump for the November election, a setback for Republicans who had hoped the revised map would help them retain their narrow House majority.

The justices declined to overturn a ruling by Missouri's highest court, which held that the newly drawn districts had been automatically suspended by a citizen petition calling for a statewide vote.

The ruling constitutes a notable setback for Republicans in a nationwide redistricting campaign that Trump urged the party to initiate last year.

Missouri’s newly drawn districts were utilized in the August primaries, yet the Missouri Supreme Court ruled in September that the state must revert to the districts established following the most recent census.

Republican state Attorney General Catherine Hanaway, who filed the appeal, argued that moving voters between districts from the primary to the general election would violate federal rights.

She also claimed it would lead to confusion.

Missouri is presently represented in the U.S. House of Representatives by six Republicans and two Democrats, all of whom were elected under congressional districts ratified by Republican state officials in 2022.

At Trump's urging, Missouri Governor Mike Kehoe called the Legislature into a special session last year to redraw congressional boundaries in their favor ahead of the midterm elections.

The revised map targeted the 5th Congressional District, held by longtime Democratic Rep. Emanuel Cleaver of Kansas City.

It reassigned portions of Kansas City to two neighboring districts represented by Republicans and stretched the remainder of Cleaver’s district far eastward into rural Republican areas.

Cleaver faced no opposition in the Democratic primary, while State Sen. Rick Brattin emerged victorious in the Republican primary within the redrawn district.

On the same day as the primary, Republican Secretary of State Denny Hoskins rejected a petition bearing thousands of signatures that sought to compel a November referendum on the map.

Hoskins argued that Missouri’s Constitution does not allow a referendum on congressional redistricting.

A lower court agreed, but the state Supreme Court reversed Hoskins’ decision.

The state's highest court ruled that the new districts were retroactively frozen in December, when the petition signatures were submitted, and therefore never became law.

On Tuesday, Hoskins, following the state court's order, placed the redistricting referendum on the November ballot as Proposition A.

The Missouri Constitution does not explicitly state that a referendum can be applied to congressional redistricting.

However, the state Supreme Court ruled that a constitutional provision allowing a referendum on "any act" of the Legislature covers legislation related to congressional redistricting.

Missouri was the second Republican-led state, after Texas, to respond to Trump's call last year to redraw congressional districts, and several other states subsequently did the same.

In total, Republicans had hoped to gain as many as 16 additional seats from the new House maps enacted in eight states — Texas, Missouri, North Carolina, Ohio, Florida, Tennessee, Louisiana and Alabama.

Democrats, whose counterattack faced several setbacks, believe they could win up to six additional seats from the new districts in California and Utah.

Whether the redistricting will deliver the anticipated gains for Republicans remains uncertain.

Historically, the president's party has tended to lose congressional seats in midterm elections, and Trump's weak approval ratings could pose an additional challenge for Republican candidates.