Gov. Mitt Romney has announced that he will veto a bill that would make the morning-after pill available without a prescription from pharmacies.

Romney told House and Senate leaders of his decision yesterday in a letter, reported the Associated Press. The letter stated that he had “promised the people of Massachusetts that as governor I would not change the laws of the Commonwealth as they relate to abortion.”

“The bill before me would change those laws and for that reason I am vetoing it,” the Republican governor wrote.

The legislation would also require hospital emergency room doctors to offer the abortifacient drug to rape victims. A provision that exempted Catholic hospitals was dropped from the legislation.

The morning-after pill prevents ovulation, stops the egg from being fertilized or stops a fertilized egg from attaching itself to the uterus wall.