But the newly formed political group funding the case, the American Foundation for Equal Rights, is opposing the request. The foundation scored a public relations coup when it persuaded the high-profile lawyers who squared off over the disputed 2000 presidential election to take on the lawsuit.

In a letter to the legal groups sent Wednesday, board president Chad Griffin, a Los Angeles-based political consultant, said the show of solidarity was coming too late since the same groups originally criticized a federal civil rights claim as premature.

"You have unrelentingly and unequivocally acted to undermine this case even before it was filed. Considering this, it is inconceivable that you would zealously and effectively litigate this case if you were successful in intervening," Griffin said. "Therefore, we will vigorously oppose any motion to intervene."

Getting more lawyers involved also would delay and unnecessarily complicate the proceedings, Griffin wrote. He said the public interest groups were welcome to continue participating as consultants.