Arizona GOP leaders are challenging which mail-in ballots can be counted in the state's ongoing U.S. Senate race.
Four Republican groups have filed a lawsuit against the way counties verify signatures on mail-in ballots.
The suit, filed against all Arizona county recorders and the secretary of state, comes amid a close race to fill GOP Sen. Jeff Flake's seat. Flake announced in October 2017 he was not running for re-election.
It claims that county recorders are allowing signature fixes on ballots by calling some voters for verification when a signature doesn't match up.
The groups are asking a judge to prevent county officials from counting those ballots, citing a state law that doesn't allow the practice after Election Day.
Democratic leaders in the state say it's a last-ditch attempt at suppressing votes. That's because Democratic Rep. Kyrsten Sinema is almost neck-and-neck with Republican Rep. Martha McSally.
It could take days for the outstanding votes to be counted.
A hearing on the issue is scheduled for Friday.