Gay rights groups attempting to intervening as full-fledged plaintiffs in a federal gay marriage lawsuit likely headed to the Supreme Court were officially rebuffed by lawyers in charge of the suit on Friday, the AP reported.

The lawsuit over a California gay marriage ban is being mounted by Theodore Olson and David Boies. The two legal titans are representing a gay couple and a lesbian couple who would like to marry but cannot because of Proposition 8, the state's voter-approved gay marriage ban upheld as constitutional by the state Supreme Court in May. The lawsuit argues that Proposition 8 violates the Equal Protection Clause of the Fourteenth Amendment of the U.S. Constitution because it discriminates against gay men and lesbians.

“Every day that Prop. 8 remains the law of California, Plaintiffs and thousands of other gay and lesbian individuals are denied fundamental rights that are cherished and enjoyed by others, and they suffer substantial, irreparable harm,” the lawsuit argues.

The move to keep the gay groups at arms length came as no surprise to anyone watching the drama unfold.

Last month, when the three gay rights groups – the National Center for Lesbian Rights, Lambda Legal and the American Civil Liberties Union (ACLU) – petitioned the court to intervene on behalf of the case, lead plaintiff the American Foundation for Equal Rights (AFER), the recently formed group that is funding the Olson-Boies suit, said they were not welcome.

In a July 8 letter to the groups, AFER President Chad Griffin said: “You have unrelentingly and unequivocally acted to undermine this case even before it was filed. In light of this, it is inconceivable that you would zealously and effectively litigate this case if you were successful in intervening. Therefore, we will vigorously oppose any motion to intervene.”

And on Friday, they vigorously opposed. Attorneys Olson and Boies argued in documents submitted to U.S. District Court Judge Vaughn Walker that allowing the groups into the legal fight would “poses a substantial risk of interference and delay.”

“Having declined to bring their own federal challenge to Proposition 8, Our Family Coalition and their counsel [the gay rights groups] should not be allowed to usurp plaintiffs' lawsuit now that it is under way and moving forward on an expedited basis,” the lawyers argued.

Previously the gay rights groups, who, along with the City of San Francisco, won the California marriage suit partially overturned by Proposition 8, had called fighting the gay marriage ban in federal court a “very high risk proposition.” But as the lawsuit gained legal momentum, the groups flipped their positions and suddenly wanted to get on-board.

If Judge Walker agrees to block the gay rights groups and the City of San Francisco, which also wants in, from becoming parties to the suit, they will be denied access to craft legal arguments and management of the case, but will be allowed to submit friend-of-the-court briefs.

Gay rights groups have shied away from taking their fight to federal courts in the past, saying the Supreme Court remains too conservative. A loss in the nation's highest court, they contend, would cause the gay marriage movement irreparable harm.

The gay rights groups wanting in on the marriage suit remain tight lipped about their support. The three groups argue the case would benefit from their experience, but none have said they believe the Olson-Boies team will ultimately prevail. This suggests they continue to harbor doubts whether the litigation will be successful, and might be attempting to limit the damage of a Supreme Court loss.

But a shift away from state courts is already underway, fueled by three additional federal filings in Los Angeles and Boston that seek to chip away at laws that restrict gay couples from the right to marry and the benefits it offers.

In another filing Friday, Olson and Boies proposed a fast-moving schedule capped by a nonjury trial before Judge Walker on December 14.