MADISON, Wis. — The Wisconsin Assembly approved a ban on the so-called morning-after pill on state college campuses, a restriction that would be the first in the nation if approved.

The vote in the lower chamber late Thursday sends the bill to the state Senate; both are controlled by Republicans. Democratic Gov. Jim Doyle said he will veto the measure if it reaches his desk.

The legislation would prohibit University of Wisconsin System health centers from advertising, prescribing or dispensing emergency contraception: drugs that can block a pregnancy in the days after sex. The state university system has 161,000 students on 26 campuses.

Republican Rep. Daniel LeMahieu introduced the bill after a health clinic serving UW-Madison students published ads in campus newspapers inviting students to call for prescriptions for the drug to use on spring break.

"Are we going to change the lifestyle of every UW student? No," LeMahieu said. "But we can tell the university that you are not going to condone it, you are not going to participate in it, and you are not going to use our tax dollars to do it."

Democrats said the bill would deny rape victims a chance to stop pregnancies and predicted it would lead to more unwanted pregnancies and surgical abortions.

Democratic Rep. Marlin Schneider called the measure "a direct frontal assault on the right to privacy, on the right of free speech, on the right of a free press."

"Apparently some in this body want to take us back to the time when the dispensing of contraception was a criminal act," Schneider said.

The morning-after pill, a heavy dosage of hormonal birth control, can work to prevent a pregnancy up to five days after unprotected sex by preventing ovulation or fertilization. Wisconsin students can get the drug at discount rates from campus pharmacies.

The drug, which requires a prescription, was approved as a contraceptive in 1998 by the Food and Drug Administration.

LeMahieu said the bill would not affect traditional birth-control pills. Attorney General Peg Lautenschlager said the bill was worded too vaguely to know for sure.

The Assembly vote made Wisconsin the first state to seriously consider banning emergency contraception on college campuses, said Elizabeth Nash, who tracks state legislation at the Alan Guttmacher Institute, a think tank that supports abortion rights.