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Montana lawmakers pushed forward with a measure Thursday that would effectively ban all abortions after 24 weeks of pregnancy, regardless of medical risks to a woman.

Critics of the bill said it could be among the most extreme anti-abortion laws in the nation, even as other states consider their own proposals that would reduce the window for legal abortions.

Montana already outlaws late-term abortions, unless the life of the woman is at risk. The legislation would require physicians to deliver a fetus at six months or later by inducing a woman into labor or performing a cesarean section.

Once the fetus is removed, doctors would be required to attempt to use whatever means to resuscitate the baby. Doctors who violate the law could be charged with a felony.

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"They either have to be a miracle worker or a felon," said Sen. Diane Sands, a Democrat from Missoula who opposed the bill. She added, "It's by far the most extreme measure I've seen ever proposed in Montana."

The measure won preliminary passage in the state Senate 32-18, mostly along partisan lines.

The bill's main proponent, Republican Sen. Albert Olszewski, said scientific and technological advances have increased the viability of fetuses.

"Now we have an issue of improved viability," said Olszewski, who is also an orthopedic surgeon.

"This bill was inspired by a real situation, a situation where a late-term pregnancy put a woman in a life-threatening condition and had to deal with this horrible decision of being told she had to terminate this pregnancy," he said.

Both sides acknowledged that the proposal could be a first of its kind. Opponents expressed concern that the law would take away medical decisions from a woman and her doctor.

The early victory by supporters will likely be short-lived. Even if the bill gets final approval in the Senate and wins support from the House — both controlled by Republicans — it would almost certainly be vetoed by Democratic Gov. Steve Bullock, who supports abortion rights.

Should it become law, the measure would be challenged by abortion-rights groups, said Martha Stahl, CEO of Planned Parenthood Montana.

"It is quite extreme, and we believe this bill is unconstitutional under Roe v. Wade," Stahl said, referring to the landmark U.S. Supreme Court decision that legalized abortion.

She said the legislation "requires women to undergo invasive medical procedures that might not be the best medical options for a woman."