In another swift blow to California’s $43 billion high-speed rail plan, federal officials Tuesday stripped all proposed funds for the mega-project this year — casting more doubt on the bullet train line’s extension into the Bay Area and Southern California.

Officials in Washington had said Monday that President Barack Obama and congressional leaders had cut this year’s high-speed rail budget from $2.5 to $1 billion during Friday’s last-second deal to avert a government shutdown. But on Tuesday, officials eliminated the final $1 billion, essentially erasing all subsidies for local high-speed rail projects, including California’s 520-mile line from San Francisco to Los Angeles.

It’s still unclear if the funding could be restored in the future, although the odds are stacked against bullet train backers. Republican deficit hawks have targeted high-speed rail as an easy choice to cut spending since being swept into office last November. And Obama, a huge bullet train booster, was set Wednesday to lay out long-term plans to slash the federal debt.

California officials still need at least $14 billion more from Uncle Sam, about half the funds required to complete the project. Now the only federal fast-train funds available are some $2 billion spurned by Florida’s governor, who scrapped the Sunshine State’s bullet train project.

The key question now: How will the state find the money to extend the project into the Bay Area — where the tracks would run along the Caltrain line between San Francisco and San Jose — and Southern California? Without extra money, a $5 billion stretch of tracks will sit in the Central Valley, with no bullet trains or riders.

California High-Speed Rail Authority officials said Tuesday they expect to get a chunk of the Florida money later this year to tide them over. But they wouldn’t discuss a backup plan in case federal funding is not restored in the long term. A new project funding plan is due to the state Legislature this fall.

“We’ll continue to need additional federal funding,” rail authority spokeswoman Rachel Wall said.

Without federal aid, officials in California face few choices to find the remaining two-thirds of funding for the system: Look to the private sector, tap cash-strapped state and local governments or put the project on hold.

An immediate delay seems unlikely for now, as officials prepare to break ground in the Central Valley next year using previous federal funds that will vanish if California does not spend them by fall 2012.

But after that initial stretch is complete, officials fear the tracks could sit unused for years as the state tries to fund the rest of the line.

Backers remained optimistic that Congress will restore the funding in future years and are not panicking.

“It’ll slow the project down, which doesn’t make any sense,” said South Bay transportation expert Rod Diridon, a former member of the California High-Speed Rail Authority board.

“It’s going to cause the overall national system to be delayed, but I don’t think it’s a death knell by any means.”

Contact Mike Rosenberg at 408-920-5705.