Washington (AFP) - A conservative federal judge in Texas handed a resounding victory to abortion opponents Friday by halting US approval of the abortion pill mifepristone, but paused implementation of his order for one week to give federal authorities time to appeal.

The medication, approved for use in the United States for more than two decades, is involved in 53 percent of all abortions in the country, or more than half a million every year.

The suit against the Food and Drug Administration is the latest step in the campaign to win a total ban on abortion following a landmark Supreme Court ruling last year.

In a sign of the legal battle to come, a federal judge in Washington state ruled almost immediately that the FDA must continue to allow the abortion pill at least in 12 states, under a suit brought by a dozen Democratic attorneys general.

The issue is likely to wind all the way to the Supreme Court, as those in the pro-abortion rights camp attempt to gain lost ground following the Supreme Court’s June 2022 decision that ended the nationwide right to abortion.

The decision in Texas was quickly branded as “deeply harmful” by the nation’s largest abortion rights group, Planned Parenthood.

“The judge’s decision in Texas today blocking the FDA’s approval of mifepristone is an outrage and exposes the weaponization of our judicial system to further restrict abortion nationwide,” the group’s president Alexis McGill Johnson.

While the FDA has never been challenged like this before on its approval of a drug that has proven safe and effective, the plaintiffs – a coalition of anti-abortion groups – counted on being able to win a national freeze on distribution of mifepristone.

“FDA’s approval of mifepristone is hereby STAYED,” Judge Matthew Kacsmaryk wrote in his decision, adding that the court was also halting “applicability of this opinion and order for seven (7) days.”

The Amarillo, Texas-based judge was appointed to the bench by Republican former president Donald Trump and confirmed by the Senate in 2019.

Kacsmaryk is a conservative Christian with a personal history of opposition to abortion and a court record of favoring right-wing causes.

- ‘Lawless ruling’ -

The case landed in his court via what critics call “judge-shopping,” in which plaintiffs take legal action in a district where the judge has a history of rulings that support their case.

Federal judges in the United States have a right to issue rulings that carry national legal force.

Democratic politicians were quick to react on social media.

Senate Majority Leader Chuck Schumer said the “ruling from an activist judge is wildly out of step with the law and sets a dangerous new precedent.”

Democratic Governor Maura Healey tweeted that “Mifepristone will stay available in Massachusetts. You have my word.”

One component of a two-drug regimen used for medication abortion, mifepristone can be used in the United States through the first 10 weeks of pregnancy.

It has a long safety record, and the FDA estimates 5.6 million Americans have used it to terminate pregnancies since it was approved.

While abortion care has halted in more than a dozen states after the Supreme Court overturned the long-established constitutional right, it is still legal in dozens more.