Jan Sramek, the controversial leader of an effort to develop a new city northeast of San Francisco, said criticism of the project’s initial secrecy amounted to an “excuse” by opponents who are looking to block much-needed housing in California.

“That whole thing has been used as an excuse by people who have hated any kind of economic development or growth for the last 30 years,” he said Thursday at the Bloomberg Tech Summit in San Francisco.

Sramek envisions his California Forever project as a green, walkable city in Solano County, but the plan has sparked opposition among some residents worried about the impact on local farmers and the environment. Sramek’s group, with backers such as former Sequoia Capital Chairman Michael Moritz and social-impact investor Laurene Powell Jobs, has won a place on the November ballot for a measure that would overturn restrictive zoning laws in the county.