A federal judge struck down a 2-year-old law that prohibits Oklahoma from recognizing adoptions by same-sex couples from other countries and U.S. states.

U.S. District Judge Robin Cauthron ruled Friday the measure violated due process rights under the U.S. Constitution because it attempted to break up families without considering the parents' fitness or the children's best interests.

Gay-rights organization Lambda Legal had challenged the law on behalf of three same-sex couples.

"Gay and lesbian parents in Oklahoma can now breathe a collective sigh of relief because their relationships with their children are no longer threatened by the state of Oklahoma," said Ken Upton, an attorney in Lambda Legal's Dallas office.

One of the plaintiffs, Heather Finstuen, said the ruling will allow her and partner Anne Magro to focus on being parents to their 7-year-old twin girls rather than worrying about the adoption law.

"This is really good news for our family," she said. "It's a huge relief."

The couple said the law endangered the legal relationship established by a New Jersey court between Finstuen and her adopted daughters. The girls were born to Magro.

The ruling was attacked by supporters of the law, which was passed by the Legislature with bipartisan support in 2004.

"It's another case of an activist court trying to legislate from the bench," said Republican Rep. Thad Balkman. "It's unfortunate that a single judge is trying to rewrite the law."