An emergency birth control pill available in dozens of countries can lower a woman's risk of an unwanted pregnancy after unprotected sex. But purchasing the pill often requires a note from a doctor or clinic. That may soon change in the United States. A panel that advises the U.S. Food and Drug Administration has recommended that the so-called "morning-after pill" be sold over the counter, without a prescription. But conservative groups are opposing such a move.

Dealing with unwanted pregnancies is part of Holly Blanchard's job. She is a nurse at the downtown Washington, D.C., clinic of Planned Parenthood.

"I've been there with my patients," she said. "I've given out positive pregnancy tests to patients who've just burst into tears. I've been with women that were in abusive relationships with their partners and conceived, and this was just one more blow. Dealing with an unintended pregnancy is totally un-fun."

But Ms. Blanchard says women facing an unintended pregnancy do have options. One of them is a product called "Plan B." If taken up to five days after unprotected sex, it can greatly lower the risk of pregnancy. Plan B contains the same chemical that has been used safely for decades in standard birth control pills. Plan B just has more of it.

The sooner it's taken, the better it works. That's why International Planned Parenthood Federation's Victoria Ward says it's important that women's access to Plan B be made as easy as possible.

"Putting barriers in her way, such as having to go to a doctor, especially if she's a low-income woman or lives in a rural area, anything like that makes it less likely that a woman can turn to this," said Ms. Ward.

Major doctors' groups, like the American Medical Association and the American College of Obstetricians and Gynecologists, are supporting the call by an FDA advisory panel to make Plan B available over-the-counter, without a doctor's prescription.

But the recommendation has drawn fire from conservatives. A group of 49 Republican congressmen has written a letter to President Bush urging the FDA to reject the recommendation. Conservative groups, like the Family Research Council, are lobbying to keep the restrictions on the morning after pill. Spokeswoman Genevieve Wood says lifting those restrictions would lead to more promiscuous behavior.

"What kind of message is it sending folks?" she asked. "That basically you can go out and have sex the night before, and then take the pill the day after, and there will be no consequences. There will be consequences."

She says those consequences include the risk of sexually transmitted diseases. And Ms. Wood says if Plan B is sold over the counter, teenagers will be the most likely consumers. She says teens shouldn't be making those kinds of choices without guidance.

"I think it takes responsibility away from parents and allows 14-, 15-year-olds to have to make those kinds of decisions on their own," explained Ms. Ward. "I don't think that's what, as a culture, we want to be encouraging.

"Let me ask you a question: when you first became sexually active, did you go ask your mom? Say, 'Hey mom, what do you think, is it OK if I have sex with whomever?" she continued.

"What generation of adolescents has ever asked their parents for permission or input, whatever they thought? Although every parental generation has tried to enforce that," added Planned Parenthood's Holly Blanchard.

Ms. Blanchard agrees teens should get advice from their parents about sex. But they often don't. And she says while abstinence is always the best birth control, people do make mistakes.

But Planned Parenthood spokeswoman Virginia Bader rejects the idea that over-the-counter Plan B will make women more promiscuous. "In the day and age when we have the diseases we have, and HIV and AIDS, it's arrogant at best to assume that a medication will incite women to behave irresponsibly," said Ms. Bader. "It has never been borne out and true."

The controversy is caught up in seemingly irreconcilable philosophical differences over abortion. Planned Parenthood estimates that emergency birth control like Plan B could prevent 800,000 abortions each year.

But the Family Research Council's Genevieve Wood says taking the pill actually causes an abortion. That's because Plan B can work after a man's sperm has fertilized a woman's egg.

"What it does do is prevent that fertilized egg from attaching to the wall of the uterus," she said. "So, yes it is, if you look at abortion that way, yes, it is an abortifacient."

The Food and Drug Administration is expected to make a final decision on Plan B in the next month. The FDA usually follows its advisory panel's recommendations.