Texas abortion providers are asking the US supreme court to block a near-total abortion ban that allows any individual the right to sue an abortion provider who violates the extreme law, a final effort to stop the unprecedented measure from taking effect on Wednesday.

Signed into law by the Republican governor, Greg Abbott, in May, Senate bill 8 bars abortion once embryonic cardiac activity is detected – typically around six weeks – and offers no exceptions for rape or incest.

The appeal to the nation’s high court comes after the largely conservative fifth circuit court of appeals on Sunday afternoon cancelled a federal district court preliminary injunction hearing on the law scheduled for Monday. Plaintiff attorneys, including the Center for Reproductive Rights, Planned Parenthood and the ACLU, who are representing more than 20 abortion providers and assistance fund groups in a lawsuit filed in July, requested the fifth circuit block the law itself, but that was denied. They are now asking the supreme court to stop the law or to at least allow district court proceedings to continue so that they can still secure an injunction.

“In less than two days, Texas politicians will have effectively overturned Roe v Wade,” said Nancy Northup, president and CEO of the Center for Reproductive Rights. “It’s cruel, unconscionable, and unlawful.”

Unlike other so-called “heartbeat” bills passed in a dozen other states and blocked by the courts, the Texas version largely shields state officials from enforcement. Instead, it empowers any private citizen in the US – regardless of their connection to the patient – to bring civil suit against not only an abortion provider but anyone who “aids or abets” the procedure, a stunningly large pool of potential legal targets that could include clinic staff, rape crisis counselors, physicians, abortion fund workers or simply a friend or family member who drives a patient to the clinic.

While those who sue can collect a minimum of $10,000 if they are successful, those unjustly sued cannot recover legal fees. The law’s radical legal provision is the first of its kind in the country.

“Anti-abortion politicians are empowering extremists to use lawsuits to harass and intimidate anyone who helps someone get an abortion,” said Kamyon Conner, executive director of Texas Equal Access Fund, a plaintiff in the lawsuit challenging SB8.

Medical professionals, attorneys, and reproductive rights groups have warned that if the law goes into effect it will drastically upend the legal and healthcare landscape in Texas. The majority of Texas women (85%) will not be able to access abortion, as most aren’t aware they are pregnant before the six-week cutoff, according to the Texas Policy Evaluation Project.

“If permitted to take effect, SB 8 would immediately and catastrophically reduce abortion access in Texas […] and likely force many abortion clinics ultimately to close,” providers wrote in their request for emergency relief from the supreme court. “Patients who can scrape together resources will be forced to attempt to leave the state to obtain an abortion, and many will be delayed until later in pregnancy. The remaining Texans who need an abortion will be forced to remain pregnant against their will or to attempt to end their pregnancies without medical supervision.”