WASHINGTON -- A streamlined California high-speed rail plan still relies on serious federal funding, even as skeptics try to sidetrack the project on Capitol Hill.

Federal grants and loans would account for about $42 billion of the total project cost now pegged at $68.4 billion, the revised business plan released this week shows. Getting the money could be a chore, as congressional Republicans continue to resist the project they cast as a high-priced pet of the Obama administration.

"Is that money in the bank? Far from it," state Sen. Joe Simitian, D-Palo Alto, said Tuesday.

California has some $3.3 billion in federal funds available to start high-speed rail construction. This money is secure, though some Republicans have discussed trying to divert it to other transportation purposes.

But within several years, the new business plan released Monday anticipates additional federal funds will resume rolling into the state. The federal dollars account for the largest share of the expected spending. Private sources, for instance, are expected to provide about $13 billion.

"The new approach helps get the initial operating segment built faster and cheaper," Jessica Kahanek, spokeswoman for rail supporter Rep. Jim Costa, D-Fresno, said Tuesday. "Once trains are moving, private capital can start moving in."

The 212-page revised business plan anticipates a combination of federal loans as well as direct grants, with some projections extending into a politically opaque future. The plan, for instance, anticipates more than $3 billion from unspecified federal sources in 2023.

"It's very much a step in the right direction," Simitian said of the revised plan, while adding that "the question that won't go away , where does the rest of the money come from?"

As part of its funding overview, the plan cites an Obama administration transportation proposal that includes billions of dollars for rail spending. The plan, however, does not recount how some Republicans called Obama's proposal dead on arrival.

"You've got a vision," Republican Sen. Jeff Sessions, R-Ala., told Transportation Secretary Ray LaHood at a February budget hearing. "It just isn't connected to reality."

The California plan declares that a "cooperative and complementary agenda for jointly pursuing federal support" will be established.

"We believe it is a high priority of the federal government," California High-Speed Rail Authority spokesman Lance Simmens said Tuesday, adding that "we have a very solid working relationship with the Department of Transportation and Federal Railroad Administration."

In anticipation of potential congressional problems, the revised business plan declares that "cap-and-trade funds are available ... as a backstop." Beginning this year, California's cap-and-trade program will collect funds from carbon-emitting polluters.

Revenue projections for the cap-and-trade program have varied extensively, from $1 billion and up. Other political priorities also will be making their claims on the money.

House Republicans already have thrown up multiple roadblocks to the California project. A House transportation bill, for instance, included an amendment from Rep. Jeff Denham, R-Turlock, that prohibited any of the five-year bill's funding from supporting California high-speed rail.

While the House transportation bill subsequently collapsed amid Republican intraparty squabbling, the GOP-controlled House has used other bills to voice similar sentiments. Last November, a separate transportation spending bill was passed without any high-speed rail funds.

The revised California business plan makes oblique reference to the congressional skepticism, citing "contentious issues at the federal level" as well as challenges with the "near-term budget scenario."