JEFFERSON CITY, Mo. (AP) — A lawsuit filed on behalf of Missouri voters by Democratic attorneys is asking a court to intervene in the state’s stalled redistricting process and draw new U.S. House maps that can be used in this year’s elections.

As of Monday, Missouri was one of only a few states that had yet to enact new congressional districts following the 2020 census. The lawsuit contends it’s unconstitutional to use the maps enacted a decade ago, because some districts now have tens of thousands more residents than others due to population shifts.

When districts don’t have equal populations, votes cast from districts with fewer people carry more weight than those from heavily populated districts, according to the lawsuit filed late Friday in Cole County Circuit Court by five voters from overpopulated districts. The suit was filed by attorneys who also represent Democrats in redistricting battles in other states.

Democrats and Republicans have been jostling nationally to redraw congressional voting districts to their advantage, as Democrats try to defend their slim majority against Republican attempts to win back the House.

Courts in Minnesota, Pennsylvania and Wisconsin already have intervened to adopt new U.S. House districts after lawmakers and governors failed to agree on plans. All three states have split political control among their legislatures and governors.

Disagreements have delayed the adoption of new U.S. House maps in the Republican-controlled states of Florida, Missouri and New Hampshire. Louisiana’s Democratic governor has not decided yet whether to veto a map passed by that state’s Republican-led Legislature. Lawsuits are challenging maps enacted in numerous other states.

In Missouri, candidates began filing for office last month despite the absence of new congressional districts. The filing period for the August primary elections closes March 29.

The Missouri House passed a proposed U.S. House map in January, but work has stalled in the Senate over an internal Republican dispute over how aggressively to draw districts in favor of the GOP. Lawmakers left the Capitol last week for spring break and aren’t scheduled to return to work until March 21.

“It is in the interests of voters, candidates, and Missouri’s entire electoral apparatus that new congressional districts be established as soon as possible, in advance of candidates’ deadline to file,” the lawsuit says while asking the court to adopt new districts.

Senators said last week that they still hope to enact new congressional districts — if not by the end of the candidate filing period, then at least by the time their session ends in mid-May. If a map is not passed until later, legislators could amend state law to reopen the candidate filing period.

“Obviously, it hasn’t been an easy process, but we feel good about the work product we’re approaching,” Senate Majority Leader Caleb Rowden said. “We’re going to do our very best to get one done.”

Paul Berry III, a Republican congressional candidate from suburban St. Louis, also filed a lawsuit last week asking a court to adopt new U.S. House districts. Berry represented himself in the lawsuit.