A Colorado proposal defining a fertilized egg as a human person has been certified for the November ballot by Colorado Secretary of State Mike Coffman, who said about 103,000 people validly signed petitions backing the proposal.

Only 76,000 signatures were required to place the proposal on the ballot, on which it will be listed as Amendment 48, according to the Associated Press.

Kristi Burton, who has led the push for the measure, said her group Colorado for Equal Rights will focus on Colorado voters who personally oppose abortion but don’t want to impose their views on others.  She said polling indicated such voters make up 20 percent of the electorate.

"Our job is to put the truth out there for the voters," she said. "Science is on our side."

Crystal Clinkenbeard, a spokeswoman for the organization Protect Families Protect Choices, said the measure isn’t “science-based” and said it made for “bad public policy.”

"We know (Burton's group) hopes to make Colorado ground zero in their fight," Clinkenbeard said.  She said her organization does not plan to challenge the signatures.