SAN FRANCISCO (Map, News) - A plan for as many as 10,000 new homes in Bayview-Hunters Point — and a possible new stadium for the San Francisco 49ers — would be “killed” if voters this June demanded that 50 percent of the housing be sold below market rates, a top city official said.

Supervisor Chris Daly has championed a ballot initiative to require that at least half of all housing built in the planned Hunters Point-Candlestick Point development be affordable to San Franciscans with household incomes between 30 percent and 80 percent of the county’s median. On Monday, Daly, along with a group of community activists, turned in to The City’s elections department what they said were about 11,000 signatures of the required 7,168 to put the measure on the ballot. The Department of Elections has 30 days to determine if the required number of signatures are valid.

“It will be close, but it should be good,” said Daly, who had attempted to put a similar measure on the ballot with four signatures from members of the Board of Supervisors, but was unable to gain the needed support from his legislative colleagues.

Lennar Corp., the project developer, has stated that 25 percent of the project’s housing 8,000 to 10,000 housing units would be priced below market rates. The project also includes 350 acres of open space, a “clean tech” business campus and a new football stadium if the 49ers decide not to relocate to Santa Clara.

Michael Cohen, director of the Mayor’s Office of Economic and Workforce Development, called the Daly-backed measure “extremely dishonest” since even a “cursory review” of it would prove that 50 percent affordability “will render the project completely infeasible.”

The ballot measure, if approved by voters, would “kill what could be one of the most important projects in the city’s history,” Cohen said.

It’s nothing new for Daly to use the ballot to pressure developers into offering more affordable housing or other benefits to The City. In 2004, Daly looked to the ballot to prompt a developer of Trinity Plaza to offer more affordable housing, and in 2005, Daly negotiated with developers of five downtown residential towers, Rincon Hill, to pay a record-setting $55 million in impact fees after threatening to put the development on the ballot.

The City should be doing more to build below-market-rate housing, Daly said, adding that 50 percent is achievable, especially if the developer’s profits are decreased.

jsabatini@examiner.com