Washington ? The highly regarded women’s health chief at the Food and Drug Administration resigned Wednesday in protest of her agency’s refusal to allow over-the-counter sales of emergency contraception.

Assistant Commissioner Susan Wood charged that FDA’s leader overruled his own scientists’ determination that the morning-after pill could safely be sold without a prescription, and stunned his employees last week by instead postponing indefinitely a decision on whether to let that happen.

“There’s fairly widespread concern about FDA’s credibility” among agency veterans as a result, Wood told The Associated Press hours after submitting her resignation Wednesday.

It was an unprecedented public show of discord for the FDA and prompted lawmakers to call for congressional hearings into whether the nation’s leading public health agency allowed politics to trump science in determining the fate of the morning-after pill called Plan B.

“It is time for the FDA to stop playing games with the health and well-being of millions of American women,” said Sens. Patty Murray, D-Wash., and Hillary Rodham Clinton, D-N.Y.