TULSA, Oklahoma - The Oklahoma Supreme Court struck down a petition that would have called a human embryo a person.

The Justices said the proposed "personhood" amendment that would have gone before voters was unconstitutional.

The Oklahoma Supreme Court got involved after the American Civil Liberties Union filed a lawsuit on behalf of six Oklahoma voters. This is the latest court decision in the debate of when human life begins.

The unanimous ruling by the state's highest court voids a petition that defined a fertilized human egg as a person.

"This is a victory," said Ryan Kiesel with ACLU Oklahoma. "It's a big day, a great day for women's health in the state of Oklahoma."

Ryan Kiesel with ACLU Oklahoma says the measure jeopardized in vitro fertilization treatments and eliminated access to common contraceptive methods.

In its decision, the state Supreme Court said the measure was unconstitutional, citing a 1992 U.S. Supreme Court ruling that upheld the right to an abortion.

"To play politics with reproductive health and the health care of women is not only bad policy, but it is unconstitutional," Kiesel said.

Personhood Oklahoma was collecting the signatures for that petition, which is backed by the larger Personhood USA.

"This represents judicial tyranny in Oklahoma," said Dan Skerbitz with Personhood Oklahoma. "They based their decision upon a prior court who ruled similarly that the people of Oklahoma do not have a right to petition their government."

Gathered outside a Tulsa abortion clinic, these supporters says the fight is far from over and the court's decision should invigorate the pro-life community even more.

"We are created in God's image and we all have the divine right to life from the moment we are created until our natural end and we believe our constitution should reflect that," Skerbitz said.

Skerbitz says the organization's attorneys will have to study the justices' decision before planning a next move. Supporters may ask the Legislature to place the issue on a statewide ballot.

A measure granting fertilized human eggs the rights and privileges of Oklahoma residents that had been approved by the Senate died in the House on Thursday.