State election officials have completed an initial step in determining whether a referendum submitted by opponents of an election law approved by the Legislature will go on Arizona's 2014 ballot.

Opponents filed what they said were more than 146,000 voter signatures on petitions to force a referendum.

Secretary of State's Office spokesman Matt Robert said samples from just over 139,000 signatures are being sent to counties for checks.

That's after the state tossed hundreds of petitions sheets as well as individual signatures for technical reasons.

According to the Arizona Capitol Times 62 percent of the remaining signatures must be deemed valid for the referendum to qualify for the ballot.

The law's changes include trimming Arizona's permanent early voting list and limiting who may return mail-in ballots for voters.