SEATTLE -- Pharmacists have sued Washington state over a new regulation that requires the sale of emergency contraception, also known as the "morning-after pill" and sold under the name Plan B.

In a lawsuit filed in federal court here, a pharmacy owner and two pharmacists say the rule that took effect Thursday coerces them into "choosing between their livelihoods and their deeply held religious and moral beliefs."

The state ruled earlier this year that druggists who believe emergency contraceptives are tantamount to abortion can't stand in the way of a patient's right to the drugs.

The state's Roman Catholic bishops and other opponents predicted a court challenge after the rule was adopted, saying the state was wrongly forcing pharmacists to administer medical treatments they consider immoral.

The plaintiffs in the lawsuit filed Wednesday are pharmacists Rhonda Mesler and Margo Thelen, and Stormans Inc., the owners of Ralph's Thriftway in Olympia, a grocery store that includes a pharmacy.

The owners of Ralph’s Thriftway said that for moral and religious reasons they oppose the use of Plan B pill because it interferes with the growth of a fertilized egg.

Gov. Chris Gregoire did not immediately respond to requests for comment from The Associated Press.

Plan B emergency contraception is a high dose of the drug found in many regular birth-control pills and can lower the risk of pregnancy by as much as 89 percent if taken within 72 hours of unprotected sex.

Some critics consider the pill related to abortion, although it is different from the abortion pill RU-486 and has no effect on women who already are pregnant.

The federal Food and Drug Administration made the morning-after pill available over the counter to adults in August.

Under the new state rule, pharmacists with personal objections to a drug can opt out by getting a co-worker to fill an order. But that applies only if the patient is able to get the prescription in the same pharmacy visit.

Pharmacies also are required to order new supplies of a drug if a patient asks for something that is not in stock.

Pharmacists are also forbidden to destroy prescriptions or harass patients, rules that were prompted by complaints from Washingtonians, chairwoman Rebecca Hille said.