Personhood Colorado filed its legal challenge Thursday in Denver District Court. The group had submitted petitions to ask Colorado voters for a third time whether to ban abortions in all circumstances.
The secretary of state ruled in August that Personhood Colorado didn't submit enough valid signatures and that there wasn't time for the group to try to complete the petition before this November's election.
The abortion foes want a judge to review the signatures and clear the measure for ballots as soon as possible, either this November or in 2014.
(Copyright 2012 by The Associated Press. All Rights Reserved.)