BATON ROUGE, LA., JUNE 26 -- The nation's most restrictive abortion bill won final legislative approval in the Louisiana Senate tonight and on Thursday should reach the desk of Gov. Charles E. "Buddy" Roemer (D), who said he would veto the measure because it did not allow exceptions for rape and incest.

Although antiabortion forces applauded wildly after the vote, declared victory and said they hoped the Louisiana action would lead to a federal court case overturning the landmark Roe v. Wade decision legalizing abortion in 1973, the ultimate fate of the legislation remained uncertain. Tonight's 24 to 15 vote indicated that the Senate might not have the two-thirds majority needed to override Roemer's veto, which is expected before the session adjourns July 9. Antiabortion sentiment is stronger in the House, where an identical bill passed by an apparently veto-proof margin two weeks earlier.

Antiabortion leaders said that they will step up the pressure on Roemer, who has always portrayed himself as a friend of the antiabortion movement. "I can tell you this much," said Sandy McDade, director of the Eagle Forum in Shreveport, Roemer's hometown, "if the governor vetoes this bill, either he doesn't intend to run for reelection or he will go up against the strongest tide he's ever seen -- the pro-life tide."

Roemer did not comment after the vote, although his aides spread the word that his views have not changed. He is expected to reaffirm his intentions at a news conference Wednesday morning.

Leaders of abortion-rights forces said they thought they had at least 15 votes in the Senate to uphold Roemer's expected veto. In a tactical sense, they were not discouraged by the Senate vote, although they said the Louisiana legislature was sending a bitter message to women across the country. "The message to women," said Robin Rothrock, director of the Louisiana League of Women Voters, "is this: If you are thinking of coming to Louisiana, and you have a working uterus, don't come."

In an unusual twist dictated as much by political strategy as by moral belief, the strongest believers on both sides combined to defeat several amendments that would have satisfied Roemer's objections. The bill's supporters said allowing exceptions for rape and incest would create a loophole and compel thousands of women to lie about their circumstances to receive abortions. They also said they would not compromise because they wanted to present the strongest possible test for the courts -- "something," said the bill's chief sponsor, Sen. Mike Cross (D), "that will fly directly in the face of Roe v. Wade."

On the other side, several senators who support abortion rights voted against the rape and incest amendments because they realized that strategy would force a veto, the only possible way they could kill the bill.

The high-ceilinged, golden-hued Senate chamber was standing room only after the crowd began gathering for the historic vote five hours before debate began. First among hundreds waiting to attend was Minka Cooper, who awoke before dawn to reach Baton Rouge from Franklin, where she has been a leader in the antiabortion movement.

"My heart is swelling today," she said. "I'm really proud of Louisiana. To think that we will be remembered in history as the state that overturned Roe v. Wade. What an honor!"

In the months since another Supreme Court decision, Webster v. Reproductive Health Services, reawakened the abortion issue in statehouses nationwide, few states have enacted restrictive legislation, and Louisiana is considered the last one this year with a chance to create a test case that could reach the high court.

West Virginia cut off Medicaid payments for abortions; Pennsylvania required women to inform their husbands before obtaining abortions, and South Carolina required parental consent for teenagers seeking abortions.

In addition, Guam banned abortions except in cases of rape, incest, fetal deformity or endangerment of the woman's life, and Idaho passed a restrictive measure vetoed by Gov. Cecil D. Andrus (D), whose objections were similar to Roemer's.

In many ways, it seemed inevitable that Louisiana would assume center stage politically and emotionally in the national abortion debate. The state's French-Catholic legal and religious heritage has long made it a stronghold for abortion foes. Louisiana laws criminalizing abortion date to an 1855 measure requiring 10 years of hard labor for doctors convicted of performing abortions.

Legislators and antiabortion leaders here had been eager to reassert the state's restrictive tradition since 1973, when Roe v. Wade led to the first legal abortion clinics in the state. Within days of the Webster decision last year, lawmakers directed prosecutors to enforce the 135-year-old law criminalizing abortion. That action was thwarted quickly by a federal court decision declaring the old law unconstitutional.

Louisiana's traditions also include a historic lack of reproductive health care and inadequate sex education, according to leaders of the abortion-rights movement. They said this leads inevitably to contradictions in the manner in which the state deals with the issue. Sex education, prohibited in the state's public schools until 1979, is taught in only six of 64 school districts.

Over the last month, as the abortion bill moved through the House and a Senate committee, citizens have crowded the shadowy hallways of the art-deco capitol skyscraper to lobby on the issue. Most have been on the antiabortion side.

At an antiabortion rally on the Capitol steps Monday, U.S. Rep. Clyde C. Holloway (R) said most of his district's voters appeared to be on hand. He said his pollsters told him that his central Louisiana district "is the strongest pro-life district ever polled in the United States."

While it was clear for weeks that the all-male Senate overwhelmingly supported some form of legislation restricting abortion, many senators appeared reluctant to pass such a severe measure. The tension in today's proceedings arose from uncertainty over how those moderates would vote in the face of intense pressure on both sides.