After the landmark win of Texas abortion providers in 2016 when a U.S. Supreme Court ruling blocked new anti-abortion efforts, activists are now trying to undo some decades-old regulations by filing another lawsuit Thursday.

The lawsuit challenges anti-abortion measures over ultrasounds, waiting periods and licensing, which stretch back at least 20 years.

Texas laws regulating abortion have proliferated over time,” the plaintiffs stated in the lawsuit. “Abortion patients and providers now face a dizzying array of medically unnecessary requirements that are difficult, time-consuming, and costly to navigate — sometimes prohibitively so," Politico reported

This is not the first time a GOP-controlled state is facing such a lawsuit. In April, Mississippi, which has only one abortion clinic, was sued by opponents over longstanding abortion laws.

The abortion providers are of the opinion that the Supreme Court opened a door for them with the 2016 ruling which struck down a law that put stricter demands on doctors and clinics. The ruling stated the benefits did not justify the obstacles people faced to get access to the clinics. Now, abortion provider Whole Woman’s Health wants the court to ensure the same standard is applied to other laws as well.

Whole Woman's CEO Amy Hagstrom Miller said after the 2013 law came into existence, more than half of the abortion clinics in Texas shut down. Five years later, now, only 3 have reopened, she added, according to Bustle. 

"This is a different strategy," Hagstrom Miller said. "Some of the things we're challenging are 10, 20 years old."

The laws that are currently being challenged include requirements that only doctors perform abortions and not clinic staff, compulsory ultrasounds in which the patient is shown pictures of the fetus, 24-hour waiting periods and licensing standards. 

A spokesman for the Republican Texas Attorney General Ken Paxton called the lawsuit a "radical pro-abortion agenda," while adding Supreme Court has already upheld similar requirements.

The comments come few months after Paxton's office asked lawmakers to expand his office in order to enforce abortion laws. 

"Abortion providers have been complying with the laws being challenged in this case for years. They are common-sense measures necessary to protect Texas women from unhygienic, unqualified clinics that put women's lives and reproductive health at risk," Paxton's spokesman Marc Rylander said.

The debate over the abortion laws and details related to them have been going on in the United States for long. Last week, Planned Parenthood in Arkansas asked a federal judge to block a state law that curbs the manner in which abortion pills are administered to women. They argued the law basically made Arkansas the first U.S. state to effectively ban that manner of abortion.