Two Latino advocacy groups sued the state of Iowa Tuesday over a law that prohibits county election officials from using information readily available in the voter registration database to fill in any information missing from a voter’s absentee ballot request. The law approved by Republican lawmakers in the final hours of the legislative session last month requires county election officials to contact the voter directly by phone, email or mail to confirm any missing information.

Supporters say it’s a voter fraud protection measure. The League of United Latin American Citizens and Majority Forward say in their lawsuit that it’s unconstitutional.