WASHINGTON -- California's ambitious high-speed rail project could slow a little under the last-minute budget deal that has kept the federal government open.

As a lead-up to what lawmakers call the largest spending cut in U.S. history, negotiators lopped $1.5 billion from federal high-speed and intercity rail funding as part of a $2 billion cut from housing and transportation spending.

The move lets states keep high-speed rail funds they've already been promised, but reduces the new money they can obtain.

The fact that high-speed rail cuts accounted for such a large portion of the $2 billion could foreshadow further funding problems down the road.

Republican congressional leaders insisted on the cuts, reflecting their resistance to a program now closely associated with the Obama administration.

Any federal high-speed rail funding cut would complicate California's plans, which call for an initial 123-mile route linking Bakersfield to rural Madera County. The state is seeking additional federal funds to extend the initial route to Merced, and possibly beyond.

The California High-Speed Rail Authority plans to use a combination of state and federal dollars to construct the project.

"California's high speed rail system is an economic game-changer for our Valley, and it's moving forward as planned," Rep. Jim Costa, D-Fresno, said Monday. "After these cuts, we will still have the opportunity to compete for almost $1 billion more dollars."

Rachel Wall, spokeswoman for the California High-Speed Rail Authority, said Monday the lost funding would have helped the state extend the system. "Obviously, if there was money available, we could put it to work."

The cut preserves $1 billion for federal high-speed and intercity rail projects for the fiscal year that ends Sept. 30. It also apparently preserves the ability of California and other states to compete for $2.4 billion in high-speed rail funds previously rejected by Florida.

The high-speed rail funding cut is part of $2 billion in housing and transportation spending reductions agreed to by White House and congressional negotiators late Friday night.

Negotiators folded the Fiscal 2011 reductions into a stop-gap measure, which keeps the government open while the finishing touches are put on a much-larger $38 billion package of cuts.

The House and Senate will vote on the overall budget-cutting bill sometime this week.

Few details were available Monday about other specific reductions, although White House officials said they will include transportation projects, housing assistance, health care programs and foreign aid.

"These are real cuts that will ... have a real impact," White House spokesman Dan Pfeiffer stressed on a White House blog. "Many will be painful, and are to programs that we support, but the fiscal situation is such that we have to act."