Supporters and opponents of gambling in Washington clashed sharply last night over the extent of financial benefits the city would get if voters approve the May 6 referendum that would legalize daily numbers and lottery games and pari-mutuel betting on dog racing and jai alai.

Retired Census Bureau official Jerry Cooper and D.C. Public Service Commissioner Wesley Long, both gambling supporters, told about 45 Capitol Hill residents at a debate that legalized gambling would help solve the city's current financial crisis, as well as attract money that is now bet in Maryland and in the city's illegal street numbers games.

Cooper, vice chairman of the umbrella group trying to legalize gambling in the nation's capital, said the referendum boiled down to a simple proposition: "Do we keep D.C. dollars in D.C. or do we continue to support Maryland?"

Long predicted that legalized gambling in the District would produce 500 new jobs and yield $35 million or more annually for the three categories designated in the proposed 43-page gambling bill: authorized, but unfunded D.C. government programs, special education instruction and nonprofit groups that provide services to D.C. residents.

But the Rev. John D. Bussey, a Baptist minister and chairman of the coalition of ministers fighting to defeat the referendum, said any claimed benefits would prove to be phantom ones and that gambling would bring more crime and profits only for those want to operate jai alai in the city.

"I'm trying to tell you the pie is not pie," he told one dubious questioner. "It's all in the sky.

"If I were a gambler I would not vote for this bill," Bussey said. "It's the legalization of more than a little innocent gambling."

He said D.C. residents who have invested in a jai alai company, Washington Jai Alai, stand to gain the most from passage of the referendum.

Long and Cooper disputed Bussey's contention, at the meeting at Logan Community School, that crime would increase here if gambling were legalized. Long noted that crime increased at a faster rate in Indiana, the only state in the northeastern quadrant of the United States without a state lottery, in the last few years than it did in Maryland, which operates one of the most successful state lotteries.