WASHINGTON – In a budget otherwise marked by fiscal austerity for everything but defense and security, President Bush had a generous about-face this year in his approach to at least one perennial money-losing program. And it has conservatives and liberals both hopping mad.

Last year, fiscal conservatives praised Mr. Bush for proposing no direct subsidies for Amtrak. The passenger rail service had cost taxpayers more than $29 billion since its formation 36 years ago, and budget watchdogs were clamoring for tough measures. Mr. Bush gave them what they wanted, then turned around and signed a bill authorizing $1.3 billion in subsidies.

This year, Mr. Bush agreed to a subsidy upfront, offering to pay for $900 million of Amtrak’s estimated $3.1 billion budget in fiscal 2007. Fiscal conservatives are decrying the offer as an inexcusable reversal from last year and citing it as fresh evidence the president is not serious about fiscal restraint.

“One year ago he said no more funding and made a strong case for it, then he lost the fight because Congress is addicted to pork,” a research fellow at the American Enterprise Institute, Veronique de Rugy,said.”But this year, instead of saying ‘You’re on parole. See what you can do,’ he said, ‘We’ll give you more money.’ If I were raising my kids the way this administration is dealing with Amtrak, they would be delinquent criminals.”

Meanwhile, Democrats, such as Senator Schumer, of New York, are calling Mr. Bush’s latest Amtrak proposal a devastating blow to commuters. In a press release issued Monday, Mr. Schumer described the $900 million subsidy as part of the administration’s “mission to cripple” the national passenger rail service by way of a 30% cut from the subsidy Congress authorized and the president ultimately approved last year.

The Bush administration’s threat to cancel subsidies last year had an affect. Soon afterward, the rail service reduced food service losses, which it had estimated at more than $100 million annually. It has slashed its workforce, which is down to 19,500 from a 2002 level of 24,000. And it drew up a strategy for additional cost-saving measures.

One of those measures, setting strict thresholds for losses on long-distance trains, is set for release in coming weeks, a spokesman for Amtrak, Clifford Black, said. But its approval is likely to meet resistance in Congress be cause Amtrak operates either through or near virtually every congressional district. Members of Congress have been reluctant to approve dramatic cuts in service even to money-losing lines.

Ms.de Rugy pointed to broad Republican support for the bill authorizing Amtrak funding last year as a sign of how difficult cutting subsidies is. Last year’s bill passed by a vote of 93 to six. Two of the senators who opposed it hail from New Hampshire: Senators Gregg and Sununu, both Republicans.

Senator Coburn,a Republican of Oklahoma and one of the most outspoken critics of pork barrel spending in the Senate, voted in favor of last year’s Amtrak subsidy. But his spokesman said yesterday that Mr. Coburn is unlikely to favor of a bill this year that adds to Mr. Bush’s current proposal. The spokesman, John Hart, also preemptively criticized Mr. Schumer and Senator Clinton, also a Democrat of New York,for efforts they are expected to make in driving up the subsidy.

“Senator Coburn would be very concerned about any effort to increase the president’s request on spending for Amtrak in a time of war and disaster recovery,” Mr. Hart said.”Amtrak is crippling itself. And if senators Schumer and Clinton are devoted to Amtrak, they can liquidate some of the pork projects they have secured for New York that may be less important than Amtrak.”

The Bush administration, which last year defended its proposal to cancel subsidies by citing Amtrak’s “unsustainably large operating losses, poor on-time performance, and increasing levels of deferred infrastructure, and fleet investment,” said yesterday that its decision to provide support this year was based largely on the rail service’s effort to restructure.

“We were encouraged by the reforms they started last year, and in order to build on those successes, we’ve significantly increased our request over last year,” a spokesman for the Office of Management and Budget, Alex Conant, said.

Critics of Mr. Bush, from both the left and the right, are poised to attack. With Amtrak set to release its own budget proposal over the next few weeks, few in Washington expect Congress to put up a fight for its reduction and fewer still expect members of Congress will neglect to tar Mr. Bush in arguing to do so.

“I don’t want to put a price tag on it yet,” Mr. Black said. “But to the extent that we are currently operating on a $1.3 billion budget, it is likely to be similar to the $1.3 billion figure, if not a little more than that.”