Judge Susan Webber Wright of the U.S. District Court for the Eastern District of Arkansas on Friday granted a preliminary injunction against the law, ruling from the bench after a hearing on a challenge brought by abortion rights advocates.

The law — passed by the state Legislature over Democratic Gov. Mike Beebe’s veto in March — was briefly the earliest abortion ban in the nation. But later the same month, North Dakota went even further, passing a ban on abortions after six weeks.

These early bans follow a spate of laws passed in the past few years banning abortions after 20 weeks into pregnancy, based on the controversial assertion that a fetus can feel pain at that point. Eleven states have passed such laws, and three of those have been challenged in court.

Opponents of these laws limiting early abortion argue they violate Supreme Court precedent established in Roe v. Wade, which says states can’t restrict abortions before viability. That’s usually considered to be around 23 weeks to 24 weeks into pregnancy.

Beebe noted the Roe precedent in his veto of the Arkansas 12-week ban, and warned that potential legal fees would add up for the state. “The adoption of blatantly unconstitutional laws can be very costly to the taxpayers of our state,” he wrote in his veto letter.

Called the Human Heartbeat Protection Act, the Arkansas law bans abortions at 12 weeks into pregnancy if a heartbeat is detected, with exceptions for cases of rape or incest, to save the life of the mother or for a lethal fetal condition.

The ACLU and the Center for Reproductive Rights filed a legal challenge to the law in April. The legislation was scheduled to take effect in August, 90 days after the state Legislature adjourned. The Center has also vowed to challenge the North Dakota law before it is implemented in August.

And the law’s opponents said they view Wright’s order as a sign that the law will be easily defeated in court.

“Today’s decision ensures that the women of Arkansas will remain protected from this blatant unconstitutional assault on their health and fundamental reproductive rights,” Nancy Northup, president of the Center for Reproductive Rights, said in a statement. “We are confident that the court will continue to uphold women’s constitutional right to make their own decisions about their pregnancies and ultimately strike down this harmful law permanently.”

Stephanie Toti, an attorney with the Center, said in a phone interview that the case was “pretty straightforward.”

“Our main argument today was that the law is a clear violation of more than 40 years of precedent and that politicians simply don’t have the authority to vote away the fundamental rights of the women in the state,” Toti continued.

“This is a really disturbing trend that we’re seeing throughout the country: states first trying to chip away at abortion and now just taking a sledgehammer to that right through these different bans,” she added.

Republican state Sen. Jason Rapert, who sponsored the 12-week ban, said he was “disappointed that the injunction actually was granted” but was encouraged that Wright stated that in her final decision, she will look carefully at whether all provisions of the law should be permanently enjoined, or only parts of it. Rapert said the judge may be inclined to uphold the piece of the law that requires a pregnant woman receive an ultrasound to detect a heartbeat.

“I believe that hopefully she will allow this statute to stand in full, but if not, I will at least take a partial win,” Rapert said.

He said he was confident Arkansas Attorney General Dustin McDaniel would appeal the case if the law were struck down.

McDaniel’s office declined to comment after the preliminary injunction was issued. When the case was filed, his spokesman Aaron Sadler said, “It is our responsibility to defend state law, and we will do so in this litigation.”