NASHVILLE (AP) — A three-judge panel on Wednesday blocked a new redistricting map for the Tennessee Senate from going into effect, saying the GOP-controlled General Assembly violated the state's constitution by improperly numbering the new districts.

The 21-page ruling gives lawmakers 15 days to fix the problem or the judges will impose an "interim apportionment map" that will apply only to the 2022 election.

Meanwhile, the filing deadline for Senate hopefuls, previously set for Thursday, is being pushed back to May 5.

A spokesperson for the Tennessee Attorney General's office did not immediately return an emailed request for comment. Republican Senate Speaker Randy McNally was still reviewing the decision and didn't have an immediate comment, said his spokesperson, Adam Kleinheider.

Last month, three voters sued the state overs its once-a-decade redistricting process. The complaint claims that Republicans who hold supermajorities in both chambers divided more counties than needed in the House to create districts with roughly equal populations, and numbered the Senate districts incorrectly.

In Wednesday's decision, the panel said the plaintiffs did not show there was a "risk of irreparable harm" to warrant blocking the House districts. However, at least one of the judges wanted to block both the House and Senate maps, according to a footnote in the ruling.

Democrats have argued that the House map also divides more counties than needed to create districts with roughly equal populations, and that it dilutes the power of minority voters. The map splits 30 counties, the maximum permitted for the state House.

The footnote added that the House map could still be blocked at a later time and the judges ordered a trial to be held on the matter.

Tennessee's constitution dictates that districts must be numbered consecutively in counties that have more than one. The newly drawn redistricting plan does not do that in Davidson County, which encompasses Nashville.

"There is no dispute about this constitutional language or what the framers of the Constitution of Tennessee meant by this language. ... Senatorial Districts are constitutionally mandated to be numbered consecutively," the judges wrote.

The lawsuit does not target the higher profile U.S. House map, which has drawn scrutiny for favoring Republicans by carving growing, left-leaning Nashville into three districts that extend far into suburbs and rural areas. A complaint has not yet been filed challenging the legality of that map.