A top U.S. scientist said Friday he had overruled his staff in rejecting over-the-counter sales of a “morning-after” contraceptive, but said lobbying from political conservatives did not sway his decision.

Dr. Steven Galson promised that the Food and Drug Administration would quickly review any new proposals from Barr Pharmaceuticals Inc. to sell the contraceptive pills, called Plan B, without a prescription.

“We’re not shutting the door on it,” Galson, acting director of the FDA’s Center for Drug Evaluation and Research, told reporters. “Wide availability of safe and effective contraceptives is important to public health.”

Galson, a medical doctor who has worked at the FDA nearly three years, is not a political appointee.

Plan B is a prescription-only emergency contraceptive that may prevent pregnancy if taken within 72 hours after sexual intercourse.

Women’s groups and others said wider access would help more women get the pills in time and reduce abortions.

Barr vowed to continue pursuing FDA approval for over-the-counter sales. The company may be able to submit new information to the FDA within months, company spokeswoman Carol Cox said.

Barr shares fell 94 cents, or 2.15 percent, to $42.86 in early afternoon trading on the New York Stock Exchange.

Late Thursday, the FDA told Barr it was rejecting the company’s application to sell Plan B without a prescription, but suggested ways the company might win future approval.

Critics, including Sen. John Kerry, charged the Bush administration with letting politics interfere with science. Kerry is President George W. Bush’s expected Democratic opponent in the November election.

Galson said he rejected Barr’s application after consulting with FDA staff scientists, who recommended approval, and the FDA commissioner’s office.

An advisory panel of outside experts also voted 23-4 last December to make Plan B available without a prescription. The FDA usually follows the suggestions of its advisory panels.

Galson said he was troubled Barr did not provide data on whether girls age 11 to 14 could use the product safely without a doctor’s input. “That really concerned me,” he said.

Conservative lawmakers and others had pressed the FDA and the White House to keep the prescription requirement. Easy access to the pills would increase promiscuity and sexually transmitted diseases, particularly among teenagers, they said.

Galson said he not discuss Plan B with anyone at the White House. A White House spokesman said FDA scientists made the decision.

The FDA told Barr it might win the agency’s blessing by providing evidence girls under 16 could use Plan B safely without a doctor’s advice. Or, the company could give details on a plan to allow girls and women age 16 and older to buy Plan B without a prescription, while keeping the prescription requirement for younger girls.

That could involve a “behind-the-counter” scenario where girls and women that meet the age requirement would not need a prescription but would have to ask a pharmacist.

Women could be intimidated by those kinds of restrictions, said Dr. Alastair Wood, a member of the advisory panel that voted for making Plan B available over the counter.

“It’s clearly against their best interest” to limit access to the drug, said Wood, professor of medicine and pharmacology at Vanderbilt University School of Medicine in Nashville.

Thirty-three countries sell emergency contraceptives without a prescription, Barr said.

Plan B contains progestin, one of the hormones in birth control pills, but at higher doses. The drug prevents pregnancy by inhibiting ovulation, Barr said.