District of Columbia voters will decide May 6 whether to legalize gambling such as bingo, lotteries and betting on dog racing, according to a ruling issued yesterday by the city's Board of Elections and Ethics.

The board's decision authorizing the referendum, the city's first under limited home rule, will permit the voters to determine the outcome of one of the most hotly contested and politically divisive issues in the city's recent history.

The vote will decide whether to legalize city-run lotteries and daily numbers games such as the ones conducted in Maryland. Other forms of gambling that would be legalized include pari-mutuel betting on jai alai, raffles and social gambling where no organizer reaps a profit.

If approved, the referendum would not legalize wagering on other sports, such as football and horse racing, or permit operation of gambling casinos.

Leaders of the D.C. Committee on Legalized Gambling, the umbrella group spearheading support for the legalization effort, broke into broad grins as the result was announced in the board's tiny meeting room.

Brant Coopersmith, the gambling committee chairman, predicted that "the gambling issue will bring people out" in large numbers for the vote. He said the group would meet soon to chart its strategy. "I'm hopeful the funds to support this will come forth," he said.

One avowed opponent of the referendum, the Rev. John D. Bussey, a Baptist minister, was present when the decision was reached. A member of the politically influential Committee of 100 Ministers, Bussey departed with a scowl on his face.

"I think it is a big mistake . . . It can't do any good for anybody," Bussey said. "We must convince people not to vote for it. We have reached the point where we are in a battle -- a war is on." He would not discuss the ministers' strategy.

The referendum, authorized under a two-year-old law that permits Washington voters to use the ballot to enact or repeal legislation, will take place at the same time as the city's presidential preference primary election.

Approval of the referendum came on a 2-to-0 vote of the board, with one member absent, after a statistical check showed that gambling backers had collected 13,520 valid signatures of voters on petitions -- 1,069 more than were required.

Yesterday's certification capped seven months of off-and-on public activity by gambling supporters, who tried at first to get the issue on the ballot last Nov. 6. Failing that, the committee renewed its signature collection campaign in the now-successful effort for the May 6 vote.

The May 6 vote is officially called an initiative. If the proposal is approved by a simple majority of the voters, it would enact a 42-page piece of detailed legislation drafted by lawyers for the gambling committee. That legislation would set up a five-member board to regulate gambling activities here, with members to be nominated by the mayor and confirmed by the City Council.

The City Council would have no further role in adopting or amending the measure if it is approved by the voters. However, Congress would review the measure for 30 legislative days with the power to veto it, the same as with measures passed by the council.

Congress amended the city's Home Rule Charter two years ago to permit such initiatives after District of Columbia voters approved of the idea in an advisory referendum authorized by the council.

Signature drives for two other initiatives are now being conducted. One would authorize the assembling of a convention that would propose measures leading to statehood for D.C. The other would legalize the personal possession and use of marijuana.

An effort by opponents of the downtown convention center to hold a binding referendum on that $100 million project failed, but the rejection has been challenged in a still unresolved lawsuit.

Under District of Columbia law, an initiative qualifies for the ballot if petitions are signed by at least 5 percent of the city's registered voters, including at least five percent from at least five of the city's eight voting wards.

According to a random sample of signatures on the gambling committee's petitions, the goal was met in all but two wards -- Ward 2, which includes downtown and the residential neighborhoods on its fringes, and Ward 3, which includes everything west of Rock Creek Park.

The weakest showing was in Ward 3, where only 491 of the 2,186 signatures required were recorded.

Coopersmith, the gambling committee chairman, said the week showing in Ward 3 distressed him, since that area has one of the highest voting turnouts in the city and could counterbalance progambling votes from other wards.

The elections board did not discuss the gambling issue in detail. After hearing the statistics and recommendations from its general counsel, William Lewis, it agreed to certify the election. Voting in favor were chairman James L. Denson and Virginia Moye. Albert C. Beveridge III was absent.

The campaign leading to the gambling initiative has cost about $22,000, including legal fees, said Coopersmith.

Most of the money has come from members of the D.C. Gambling Study Commission, a council-created citizen group that Coopersmith headed, as well as by retail liquor dealers and stockholders in the Washington Jai Alai Corp. The latter firm hopes to win a franchise to conduct games, with parimutual wagering, in the city.