The National Organization for Marriage said Monday that it will file a motion seeking to intervene in the

.

John Eastman, the group's chairman,

that a challenge to Oregon's marriage law would proceed in federal court with no meaningful defense of the constitutional amendment adopted overwhelmingly by voters."

At this point, no one with legal standing in the case is defending the 2004 constitutional measure approved by voters that limits marriage in Oregon to one man and one woman. U.S. District Judge Michael McShane will hear oral arguments in the case Wednesday.

Oregon Attorney General Ellen Rosenblum announced earlier this year that she would not defend the state constitutional provision because it conflicts with federal equal rights protections.

"If our motion to intervene is granted, we intend to fully and aggressively defend the state constitutional amendment," Eastman said. he organization said the motion to intervene will be filed on behalf of the group's members in Oregon, including a county clerk, professionals in the wedding industry and voters from the state.

David Fidanque of the Oregon chapter of the American Civil Liberties Union, which is seeking to overturn the state law prohibiting same-sex marriage, said his attorneys "will oppose any motion to intervene because it is coming at such a late date."

Fidanque said there was no reason for the National Organization for Marriage to wait so late because it has been clear

the same-sex marriage prohibition.

Eastman said his organization decided to intervene after Rosenblum's office filed a brief in late March laying out why she thought Oregon's ban should be overturned. And he said it took a while to get their case in order after that.

Kristina Edmunson, a spokeswoman for Rosenblum, said she could not comment on the motion because nobody in the attorney general's office had seen it yet.

Even if the marriage group is allowed to intervene, that doesn't necessarily mean the group would have the legal standing to appeal a decision by McShane to overturn Oregon law.

, which let stand a federal ruling allowing same-sex marriage in California, expressly limited which parties could appeal.

Among the legal and political insiders following the Oregon case, there was much speculation about the National Organization for Marriage's strategy.

Some said they thought it might be aimed at slowing a decision in this case so that backers of a same-sex marriage initiative will have to take their fight to the ballot in November. They had hoped that a quick ruling by the judge would allow them to drop the ballot measure.

Mike Marshall, campaign manager of Oregon United for Marriage, said he thought the action by the National Organization for Marriage had a "slim chance of success" and could actually be a ploy aimed at forcing backers of gay marriage to spend more money on an initiative campaign.

That, in turn, would reduce the amount of money they have to combat a proposed ballot measure that would allow individuals and businesses to refuse to serve gay weddings if they have religious objections.

-- Jeff Mapes