After three days of emotional debate on the constitutionality of limiting a woman's right to an abortion, the Senate overwhelmingly approved a ban Thursday on a late-term procedure that abortion opponents called "barbaric."

The Partial Birth Abortion Ban Act of 2003 received a 64-33 vote. It now heads to the Republican-led House, which passed the ban last year before it was stopped in the then-controlled Democratic Senate.  

House Republicans said they expect to pass the bill by Easter. President Bush has said he would sign the bill if it reaches his desk.

"Partial-birth abortion is an abhorrent procedure that offends human dignity, and I commend the Senate for passing legislation to ban it," Bush said in a prepared statement. "Today's action is an important step toward building a culture of life in America."

But Thursday's vote showed that several Democrats also oppose the procedure, which consists of partially delivering a fetus in the 20th and 26th week, then puncturing the brain cavity. In the event of a breech delivery, partial birth would mean "any part of the fetal trunk past the navel is outside the body of the mother."

The bill makes it illegal for doctors to commit the "overt act" of killing the partially delivered fetus unless the mother suffers from a pre-existing condition that would amount to a full-term pregnancy endangering her life.

"This is a great day for humanity. I am delighted to see us taking the step to eliminate this practice that some of our colleagues in the past have called the closest thing to infanticide," said Sen. Sam Brownback, R-Kan.

"It will become law this year," he said.

But not everyone believes that the late-term procedure should be banned, and some accused the bill's Republican sponsors of trying to roll back the clock on Roe v. Wade, the 1973 Supreme Court case that made it legal for a woman to seek an abortion.

"This bill is unconstitutional," argued Sen. Barbara Boxer, D-Calif., citing the lack of an exemption in cases where the mother develops a life-threatening condition as the result of pregnancy.

The debate over partial birth abortion has been brewing since Republicans took control of the House in 1995.

Twice, the Congress passed a partial birth abortion ban, but former President Clinton vetoed it. In 2000, the Supreme Court derailed efforts to pass a ban when it invalidated a Nebraska state law that closely resembled the measure moving through the House and Senate.

Abortion rights advocates scored one victory on Wednesday when the Senate voted 52-46 in support of Roe v. Wade.

It was the first referendum on the 30-year-old ruling since the new Congress convened in January, and nine of the 11 newcomers to the Senate signaled opposition to the ruling.

That was a nonbinding vote, and on the legislative skirmishes that counted, abortion foes were in command.

On Wednesday, a critical test of the bill's future success came when lawmakers voted 60-38 to ban exceptions in the case of risk of "grievous injury" to the health of the mother. Critics of the measure said the amendment rendered the prohibition all but meaningless.

"It doesn't ban abortion, which is what some people want. And it doesn't get the government out of the picture, which is what some other people want," said Sen. Dick Durbin, D-Ill., who sponsored the substitute. "Instead, it tries to draw a line, a good faith line of where we will allow abortions in late-term pregnancies."

After that failed, lawmakers also rejected by a 56-42 vote a call to have the bill rewritten in committee to address "constitutional issues raised by the Supreme Court" in a 2000 ruling.

Later in the day, in a final triumph for abortion foes, the Senate rejected a second attempt to substitute a ban on abortions after the fetus is viable outside the mother. That proposal included exceptions for the life and health of the mother, and failed, 60-35.

The Associated Press contributed to this report.