Maricopa County wants to participate in a federal court case involving the Arizona Legislature's challenge to the state's current map of congressional districts.
County officials say they aren't taking a position on the challenge itself but have a stake in the case because its outcome could affect how the county conducts elections.
The request to intervene in the case is pending in federal court.
The Republican-controlled Legislature's lawsuit seeks an order blocking use of the congressional districts drawn by the Arizona Independent Redistricting Commission.
The suit said the state constitutional amendment approved by voters in 2000 to create the commission violates a federal constitutional provision authorizing state legislatures to regulate congressional elections.
The commission said that argument has been rejected before and that the Legislature waited too long to sue.