The Republican-controlled Arizona Legislature wants a federal court to immediately block use of congressional district maps created by the Arizona Independent Redistricting Commission.
The Legislature, led by Senate President Andy Biggs and House Speaker Andy Tobin, sued over the maps in June 2012. Their lawyers asked for a preliminary injunction in a filing Friday.
They argue the U.S. Constitution gives state legislatures the right to regulate congressional elections and that voter-approved Proposition 106 creating the commission in 2000 took that power away.
The commission argues the Supreme Court has rejected that argument previously and the Legislature waited too long to make the claim.
Three federal judges have been appointed to hear the challenge.
Another three-judge panel is weighing a separate challenge to legislative district boundaries adopted by the commission in January 2012.
Republicans complained during and after the redistricting process that the commission was tilting in favor of Democrats.
Under the redistricting, Arizonans elected five Democrats and four Republicans to Congress last year. In the state House, 36 Republicans and 24 Democrats were elected, and in the state Senate, 17 Republicans and 13 Democrats were elected.