Norma McCorvey, who went by the name Jane Roe in the landmark Roe v. Wade ruling but later joined the anti-abortion movement, filed a motion in Dallas federal court claiming changes in the law and advances in medicine had rendered the court's original decision unjust.

At a Dallas rally, she told supporters she regretted her part in the original lawsuit.

"I want to thank all the wonderful women that are standing here. I'm so sorry that I filed that affidavit," McCorvey said.

"I long for the day that justice will be done and the burden from all these deaths will be removed from my shoulders," she said in a separate statement.

Planned Parenthood president Gloria Feldt said the case was not viewed as a threat to abortion rights.

"We don't expect the court to take it seriously. And the reason is because it was a good decision," she told Reuters. "Roe v. Wade enabled women to participate in the social, financial and political life of this country."

The move is the latest challenge to U.S. abortion rights and comes after the House of Representatives and the Senate each approved a ban on a procedure critics call "partial birth" abortion. Minor differences in the two versions remain to be worked out before the legislation goes to the White House.

The ban, supported by President Bush, would be the first time a specific abortion procedure has been criminalized since the 1973 Supreme Court decision.

In Tuesday's motion, written by a Texas-based conservative legal group called the Justice Foundation, McCorvey said Roe v. Wade was decided on false assumptions and that no meaningful trial was held to determine the facts