As promised, the Arkansas chapter of the American Civil Liberties Union filed a lawsuit Tuesday challenging a recently passed state law that bans most abortions at 12 weeks.

The ACLU filed the suit in U.S. District Court in Little Rock on behalf of two physicians, Louis Jerry Edwards and Tom Tvedten, who provide abortion services at a Little Rock clinic. The suit, which names the director and members of the state Medical Board as defendants, asks for a ruling that Act 301 of 2013 is unconstitutional, an injunction restraining the board from enforcing it and an award of attorneys’ fees and costs.

Act 301 requires a woman seeking an abortion at 12 weeks or later into a pregnancy to receive an abdominal ultrasound to check for a fetal heartbeat. If a heartbeat is detected, the law prohibits an abortion from being performed except in cases of rape, incest, medical emergencies or fetal anomalies that would not allow the child to live after birth.

A physician who violates the law would lose his medical license.

The U.S. Supreme Court has said states cannot ban abortions before a fetus becomes viable, or able to survive outside the womb. Doctors generally consider a fetus viable at 23 or 24 weeks.

Gov. Mike Beebe vetoed the ban, which he said was unconstitutional, but the House and Senate overrode his veto in early March.

"The act … denies plaintiffs’ patients their constitutionally guaranteed right to decide to end a pre-viability pregnancy," the ACLU’s suit alleges.

Rita Sklar, executive director of the Arkansas ACLU, announced the lawsuit in a news conference at the state Capitol.

"The U.S. Supreme Court has recognized that the Constitution protects a woman’s ability to make her own decision about an abortion, but our state Legislature ignored the law and voted to take a woman’s decision-making ability away," she said. "So now it comes to this: We must ask the court to make sure this decision stays with a woman, her family and her doctor, where it belongs."

The suit asks for an injunction before the law takes effect in order to prevent "irreparable harm." The law is set to take effect 90 days after the legislative session formally adjourns.

Sen. Jason Rapert, R-Conway, who sponsored the legislation that became Act 301, said Tuesday that the ACLU "has a history of opposing any legislation that would actually save the lives of unborn children. They’ve made good on that promise."

He said Attorney General Dustin McDaniel has pledged that his office will defend the law to the best of its ability and noted that help is available from the Liberty Counsel, a nonprofit law firm that defends conservative causes.

"The Liberty Counsel has pledged their coordination and support, in fact would take up the defense if the attorney general decided that he wanted to just allow them to handle the situation. That will be up to the attorney general," Rapert said.

Jerry Cox, president of the Christian conservative Family Council, was present for the news conference and told reporters afterward that if the state has to spend taxpayer dollars to defend the law in court, he will consider it "money well spent."

"Sure, it challenges the status quo," Cox said. "But that’s how things get changed."

Act 301 was the strictest abortion ban in the country until North Dakota passed a six-week abortion ban in late March.