WASHINGTON » The morning-after pill might become as easy to buy as aspirin.

In a scathing rebuke accusing the Obama administration of letting election-year politics trump science, a federal judge ruled today that there should be no age restrictions on the sale of emergency contraception without a doctor’s prescription.

Today, buyers must prove at the pharmacy that they’re 17 or older; everyone else must see a doctor first. U.S. District Judge Edward Korman of New York blasted the government’s decision on age limits as "arbitrary, capricious and unreasonable," and ordered an end to the restrictions within 30 days.

The Justice Department was evaluating whether to appeal, and spokeswoman Allison Price said there would be a prompt decision.

President Barack Obama had supported the 2011 decision setting age limits, and White House spokesman Jay Carney said today the president hasn’t changed his position. "He believes it was the right common-sense approach to this issue," Carney said.

If the court order stands, Plan B One-Step and its generic versions could move from behind pharmacy counters out to drugstore shelves — ending a decade-plus struggle by women’s groups for easier access to these pills, which can prevent pregnancy if taken soon enough after unprotected sex.

Saying the sales restrictions can make it hard for women of any age to buy the pills, Korman described the administration’s decision, in the year before the 2012 presidential and congressional elections, as "politically motivated, scientifically unjustified and contrary to agency precedent."

Women’s health specialists hailed the ruling.

"It has been clear for a long time that the medical and scientific community think this should be fully over the counter and is safe for women of all ages to use," said Dr. Susan Wood, who resigned as FDA’s women’s health chief in 2005 to protest Bush administration foot-dragging over Plan B.

Half the nation’s pregnancies every year are unintended. Doctors’ groups say more access to morning-after pills — by putting them near the condoms and spermicides so people can learn about them and buy them quickly — could cut those numbers. They see little risk in overuse, as the pills cost $40 to $50 apiece.

"The fact that it’s over the counter does not make people have sex," said Dr. Angela Diaz, director of New York’s Mount Sinai Adolescent Health Center. "Sixty percent of young people are sexually active by 12th grade, and the more tools we have to help them be responsible, the better."

Social conservatives criticized the ruling.

"There is a real danger that Plan B may be given to young girls, under coercion or without their consent," said Anna Higgins of the Family Research Council. "The involvement of parents and medical professionals acts as a safeguard for these young girls. However, today’s ruling removes these common-sense protections."

Deirdre McQuade, spokeswoman for the U.S. Conference of Catholic Bishops, said: "Plan B does not prevent or treat any disease, but makes young adolescent girls more available to sexual predators. The court’s action undermines parents’ ability to protect their daughters from such exploitation and from the adverse effects of the drug itself."

Absent an appeal or a government request for more time to prepare one, the ruling would take effect in 30 days, meaning that over-the-counter sales could start then.

The Food and Drug Administration actually was preparing to allow over-the-counter sale of Plan B One-Step with no age limits in late 2011 when Health and Human Services Secretary Kathleen Sebelius, in an unprecedented move, overruled her own scientists. Sebelius said some girls as young as 11 are physically capable of bearing children but shouldn’t be able to buy the pregnancy-preventing pill on their own.

The federal judge dismissed that argument.

"This case is not about the potential misuse of Plan B by 11-year-olds," said Korman, who called the pills safe for girls but said the number using them "is likely to be minuscule" as less than 3 percent of girls under age 13 are sexually active.

He cited the Administrative Procedure Act as granting a judge the authority to set aside an agency’s rulings "if they are ‘arbitrary, capricious, an abuse of discretion or otherwise not in accordance with law.’"

Korman said regulation requires that when the FDA allows nonprescription drug sales, "the standards are the same for aspirin and for contraceptives" — and he ultimately determined that the government violated those standards in the case of Plan B.

"The decision that the agency was forced to make, contrary to its own policies and judgment, is not entitled to any deference," Korman concluded. "Indeed, it is hardly clear that the secretary had the power to issue the order, and if she did have that authority, her decision was arbitrary, capricious, and unreasonable."

It was the judge’s latest ruling in a lawsuit filed by the Center for Reproductive Rights and dating back to 2005 that pushed for unfettered over-the-counter access to Plan B.

Korman didn’t spare the FDA from criticism, citing "a strong showing of bad faith and improper political influence" going back to the Bush administration, when the center filed a citizen’s petition to try to get the agency to act. That was followed by the lawsuit.

"More than twelve years have passed since the citizen petition was filed and eight years since this lawsuit commenced," Korman wrote in a decision dated Thursday and released today. "The FDA has engaged in intolerable delays in processing the petition. Indeed, it could accurately be described as an administrative agency filibuster."

The judge said the FDA decided after 11 months, 47,000 public comments and hundreds of thousands, if not millions, of dollars spent, that it did not need rulemaking on the subject.

"The plaintiffs should not be forced to endure, nor should the agency’s misconduct be rewarded by, an exercise that permits the FDA to engage in further delay and obstruction," he wrote.

Four years ago, Korman was highly critical of the Bush administration’s initial handling of the issue when he ordered the FDA to let 17-year-olds obtain the medication, instead of setting the age at 18. At the time, he accused the government of letting "political considerations, delays and implausible justifications for decision-making" cloud the approval process.

The morning-after pill contains a higher dose of the female progestin hormone than is in regular birth control pills. Taking it within 72 hours of rape, condom failure or just forgetting regular contraception can cut the chances of pregnancy by up to 89 percent. But it works best within the first 24 hours.

If a woman already is pregnant, the pill has no effect. It prevents ovulation or fertilization of an egg. According to the medical definition, pregnancy doesn’t begin until a fertilized egg implants itself into the wall of the uterus. Still, some critics say Plan B is the equivalent of an abortion pill because it may also be able to prevent a fertilized egg from attaching to the uterus, a contention that many scientists — and Korman, in his ruling — said has been discredited.

Neumeister reported from New York. Associated Press writer Ricardo Alonso-Zaldivar contributed to this report.