Washington (AFP) – The conservative-majority US Supreme Court hears challenges on Monday to the most restrictive law passed since abortion was made a constitutional right nearly 50 years ago — a Texas bill that bans a woman from terminating a pregnancy after six weeks.

Dozens of protesters gathered outside the court in downtown Washington ahead of two hours of arguments before the nine-member panel.

“Keep Your Laws Off Our Bodies,” read signs carried by demonstrators supporting the right to an abortion. “Let Their Hearts Beat,” read signs carried by anti-abortion protesters.

The “Texas Heartbeat Act” bans abortions after a heartbeat can be detected in the womb, which is normally around six weeks — before many women even know they are pregnant — and makes no exceptions for rape or incest.

The Supreme Court, which has a 6-3 conservative majority after Donald Trump nominated three justices, is to hear two hours of arguments in a case that has sparked a fierce legal and political battle.

The Supreme Court was asked by abortion providers to block the law when it took effect on September 1, but the court declined to do so citing “procedural issues.”

The case is now back before the top court after Texas, the second-largest US state, was sued by Democratic President Joe Biden’s Justice Department and a coalition of abortion providers, who say the restrictions are unconstitutional.

Biden was among those who criticized the court for failing to tackle a law that “blatantly violates the constitutional right established under Roe v. Wade,” the landmark 1973 Supreme Court ruling enshrining a woman’s legal right to an abortion.

Laws restricting abortion have been passed in other Republican-led states but were struck down by the courts because they violated previous Supreme Court rulings that guaranteed the right to an abortion until the fetus is viable outside the womb, which is typically around 22 to 24 weeks.

‘Why are they making me keep it?’

Texas Senate Bill 8 (SB8) differs from other efforts in that it insulates the state by giving members of the public the right to sue doctors who perform abortions, or anyone who helps facilitate them, once a heartbeat is detected.

They can be rewarded with $10,000 for initiating cases that land in court, prompting criticism that the state is encouraging people to take the law into their own hands.

“The most pernicious thing about the Texas law is it sort of creates a vigilante system, where people get rewards,” Biden said at the White House in September.

Many clinics in Texas — fearful of potentially ruinous lawsuits — have closed their doors, and the number of abortions in the state fell to 2,100 in September from 4,300 a year earlier, according to a University of Texas study.

Planned Parenthood, one of the largest providers of women’s health care in the nation, sent a 30-page legal brief to the court containing testimony from women and doctors affected by the Texas law.

One patient, identified as I.O., was 12 years old.

“The mother said they could not travel out of State — they had barely made it to the Texas health center,” the brief said. 

The 12-year-old was quoted as saying, “Mom, it was an accident. Why are they making me keep it?”

The Supreme Court could make a decision at any time after oral arguments but is widely expected to rule before hearing another abortion case on December 1.

In that case, the court will hear a challenge to a Mississippi law that bans abortion after 15 weeks.

At least four justices appear ready to block the Texas law: the three liberals on the court and Chief Justice John Roberts, who expressed concerns about SB8 when it previously appeared before the court.

“Now the question is, ‘Is there a fifth vote?'” Steve Vladeck, a law professor at the University of Texas, asked on a podcast.