By Brendan Pierson and Nate Raymond

(Reuters) -Arizona’s top court revived a law dating to 1864 on Tuesday that bans abortion in virtual all instances, another setback for reproductive rights in a state where the procedure already was barred starting at 15 weeks of pregnancy.

The Arizona Supreme Court ruled 4-2 in favor of an anti-abortion obstetrician and a county prosecutor who took up defense of the law after the state’s Democratic attorney general had declined to so.

Justice John Lopez, who like all of the court’s members was appointed by a Republican governor, wrote that to date, the state’s legislature “has never affirmatively created a right to, or independently authorized, elective abortion.”

“We defer, as we are constitutionally obligated to do, to the legislature’s judgment, which is accountable to, and thus reflects, the mutable will of our citizens,” Lopez wrote.

The fight over abortion access in Arizona is far from over. A group of abortion rights advocates last week said it gathered enough signatures to put before voters in November a ballot measure that would enshrine in the state’s constitution a right to an abortion until fetal viability.

Arizona Attorney General Kris Mayes, a Democrat, in a statement called the ruling “unconscionable and an affront to freedom,” and stressed that she would not while in her position prosecute any doctor or woman under the “draconian law.”

“Today’s decision to reimpose a law from a time when Arizona wasn’t a state, the Civil War was raging, and women couldn’t even vote will go down in history as a stain on our state,” she said.

The ruling marked the latest legal setback in days for abortion rights, following a ruling last week by the Florida Supreme Court that cleared the way for a Republican-backed law banning abortion after six weeks of pregnancy to take effect.

At issue in the Arizona Supreme Court case was an 1864 law, enacted before Arizona became a U.S. state that banned abortions except to save the woman’s life, and imposed a penalty of up to five years in prison for anyone who performs an abortion.

Planned Parenthood, which provides abortions and other healthcare services, sued the state in 1971 to challenge the 19th century law. A judge ruled in Planned Parenthood’s favor and issued an order blocking the law following the U.S. Supreme Court’s landmark 1973 ruling in Roe v. Wade that recognized a constitutional right to abortion and legalized the procedure nationwide.

In March 2022, the governor at the time, Republican Doug Ducey, signed the new law that banned abortion after 15 weeks. Like the 1864 statute, it carries a penalty of up to five years in prison for anyone who performs or helps a woman obtain an abortion.

The U.S. Supreme Court cleared the way for the new law to take effect when it overturned Roe in June 2022. A number of states since have enacted Republican-backed abortion restrictions.

In July 2022, the Republican Attorney General Mark Brnovich filed a motion in the Planned Parenthood case to challenge the judicial order that blocked the 1864 law and let prosecutors enforce the ban. A court granted that request in September 2022.

After Planned Parenthood appealed, a state appellate court in December 2022 once again blocked the 1864 ban from being enforced against doctors, though it allowed enforcement against non-physicians who perform abortions. The state’s newly elected Democratic governor, Katie Hobbs, and attorney general Mayes, declined to appeal further.

That led obstetrician Eric Hazelrigg and Yavapai County Attorney Dennis McGrane to intervene in the case to defend the 1864 law before the state’s Supreme Court. Hazelrigg runs a network of crisis pregnancy centers – facilities where pregnant women are counseled against from having abortions.

They are represented by Alliance Defending Freedom, a conservative legal group behind other challenges to abortion rights including an effort to restrict access to the abortion pill.