Supporters of a referendum to guarantee shelter to the city's homeless people began their campaign for it yesterday with a rollicking birthday party in honor of the late homeless advocate Mitch Snyder.

About 100 supporters of the Community for Creative Non-Violence -- many wearing colored hats and blowing noisemakers -- gathered on the steps of the District Building to sing "Happy Birthday," throw confetti and blow out the 47 candles on Snyder's cake.

Then, as CCNV's Carol Fennelly said, they gave "Mitch the present he wanted most": handing in petitions to the Board of Elections for a November referendum that would restore Initiative 17, the 1984 law that guaranteed overnight shelter for the homeless. CCNV said the petitions contained more than 43,000 signatures.

In June, the D.C. Council limited Initiative 17 by placing cost-cutting restrictions on the amount of time the homeless could spend in city shelters.

CCNV organizers said the number of signatures collected -- about three times the 14,229 signatures required -- signifies the depth of public support for what will be known as Referendum 005. They said yesterday's festivities were the first of many campaign efforts that will lead to victory.

In their path, however, are the city's growing budget problems, several attention-grabbing local races, and what some see as waning public concern for the homeless.

Since Snyder's suicide in July, said Ronald Walters, the chairman of Howard University's political science department, "CCNV is without a champion skilled in the manipulating of public opinion."

Walters said that if mayoral and council candidates do not voice support for the referendum, it could go unnoticed in a busy election season.

Fennelly said Snyder's absence would not greatly affect the effort.

"I know that the support was out there before he died," she said.

She added, however, that to match Snyder's ability to attract attention with hunger strikes and visits from Hollywood celebrities, "we'll have to get more creative."

"But," she said, "creative is our middle name."

Fennelly said CCNV has "500 volunteers ready to go" to begin a massive education campaign that will include door-to-door canvassing, speaking in churches and working through the city's Advisory Neighborhood Commissions.

Council member H.R. Crawford (D-Ward 7), who sponsored the legislation that rolled back Initiative 17, said he hoped the referendum would fail.

"This is just too expensive," he said. "Ultimately, the people will recognize that Initiative 17 has put a hold on the city's purse strings that will force us to cut back on other social service programs."

Fennelly bristled at that: "The homeless budget is less than 1 percent of the D.C. budget," she said.