The director of the ACLU's LGBT project has called a new lawsuit that seeks to strike down California's gay marriage ban, Proposition 8, through the federal courts a “very high risk proposition.”

The new lawsuit filed Friday joins two legal titans – and former adversaries – in representing a gay couple and a lesbian couple who would like to marry in California but cannot because of Proposition 8, the state's voter-approved gay marriage ban upheld Tuesday as constitutional by the state Supreme Court.

Ted Olson and David Boies litigated on opposite sides of the Bush vs. Gore Supreme Court case that decided the 2000 presidential election. Olson also defended President Reagan during the Iran-Contra scandal and has served on the board of directors of The American Spectator.

The complaint claims California officials – including Governor Arnold Schwarzenegger and Attorney General Jerry Brown – are enforcing an unconstitutional law, Proposition 8, which denies “fundamental liberties … protected by the Due Process Clause” of the U.S. Constitution and violates the Equal Protection Clause of the Fourteenth Amendment.

“Prop. 8 impinges on fundamental liberties by denying gay and lesbian individuals the opportunity to marry civilly and to enter the same officially sanctioned family relationship with their loved ones as opposite-sex individuals,” the complaint reads.

Olson and Boies, who have been retained by the American Foundation for Equal Rights, also called for an injunction against Proposition 8, which would immediately reinstate gay marriage in California until the lawsuit is settled. Olson said he believes the case would reach the Supreme Court.

While a win in the Supreme Court would open gay marriage nationwide, a loss would likely set the movement back possibly decades; leaving gay activists to call the move “premature.”

“Successful change involves building blocks,” Matt Coles, director of ACLU's LGBT project, told the Wall Street Journal's law blog. “You build constitutional principles alongside efforts at the societal and legislative levels. They're jumping over the process and going straight to the end. From where we sit, this is a very high-risk proposition.”

“In our view, the best way to win marriage equality nationally is to continue working state by state, not to bring premature federal challenges that pose a very high risk of setting a negative U.S. Supreme Court precedent,” Shannon Minter, legal director of National Center for Lesbian Rights, told the AP.

For his part, Olson, considered a conservative constitutional litigator, says he is in the fight to win and would not take on such a challenge if he did not believe the court was prepared.

“Yesterday, the California Supreme Court said that the California Constitution compels the State to discriminate against gay men and lesbians who have the temerity to wish to express their love and commitment to one another by getting married,” Olson said in a statement Wednesday. “These are our neighbors, co-workers, teachers, friends, and family, and courtesy of Prop. 8, California now prohibits them from exercising this basic, fundamental right of humanity. Whatever discrimination California law now might permit, I can assure you, the United States Constitution does not.”

And when asked about the timing of the lawsuit during a press conference in Los Angeles Wednesday, Olson replied: “There will be many people who will think this is not the time to go to federal. Both David [Boies] and I have studied the court for more years than probably either one of us would like to admit. We think we know what we are doing.”