A two-month-old House-Senate standoff over the 2005 budget burst into public acrimony yesterday, when the GOP House speaker questioned Sen. John McCain's credentials as a Republican and suggested that the decorated Vietnam War veteran did not understand the meaning of sacrifice.

The battle over the budget has highlighted rising tensions between a House dominated by conservatives and a Senate where moderates still wield considerable influence, with President Bush's agenda caught in the crossfire.

House Speaker J. Dennis Hastert (Ill.) lectured McCain (Ariz.) -- an outspoken opponent of Bush's tax cuts -- over war sacrifices, drawing a blistering retort from McCain, who nearly died of war wounds in a North Vietnamese prison camp.

On Tuesday, McCain gave a speech excoriating both political parties for refusing to sacrifice their tax cutting and spending agendas in wartime. At the Capitol yesterday, Hastert shot back: "If you want to see sacrifice, John McCain ought to visit our young men and women at Walter Reed [Army Medical Center] and Bethesda [Naval Hospital]. There's the sacrifice in this country."

Amid such rancor, Bush will travel to Capitol Hill this morning to try to rally Republicans on both sides of the Capitol behind his flagging agenda and reassure them that his campaign is on course despite his drop in the polls.

The hurriedly scheduled trip was designed to assuage the trepidation of lawmakers as they head back to their states and districts for the Memorial Day break.

"Our guys need this," a House Republican aide said. "They can go home and say, 'We met with the president. He has a vision. We know where he's going. We trust him. Don't believe what the media's telling you.' "

Democratic officials said they are preparing to accuse Republicans of mismanagement and failure to govern if the party cannot produce a final budget.

Deep cracks are appearing within the GOP, not only over tax policy and the budget deficit but also the conduct of the war in Iraq.

Earlier this week, House Majority Leader Tom DeLay (R-Tex.) and House Armed Services Committee Chairman Duncan Hunter (R-Calif.) castigated Senate Republicans for continuing their public investigations of the Abu Ghraib prison abuse scandal, accusing them of undermining the war effort.

"We've got 135,000 kids over there that need leadership, and their leadership can't be dragged back to Washington every couple of days," Hunter said.

The nasty exchange between McCain and Hastert began with a comment the senator made at a think-tank conference on the budget deficit on Tuesday. "My friends, we are at war. Throughout our history, wartime has been a time of sacrifice," McCain said. "But about the only sacrifice taking place is that by the brave men and women fighting to defend and protect the liberties we hold so dear, and that of their families. It is time for others to step up and start sacrificing."

Yesterday, Hastert questioned whether McCain is really a member of Bush's party. "A Republican?" Hastert said with feigned incredulity. He then criticized McCain's opposition to extending tax cuts in wartime.

"We're trying to make sure that they have the ability to fight this war, that they have the wherewithal to be able to do it," Hastert said. "And at the same time, we have to react to keep this country strong not only militarily but economically."

McCain retorted: "The speaker is correct in that nothing we are called upon to do comes close to matching the heroism of our troops. All we are called upon to do is to not spend our nation into bankruptcy while our soldiers risk their lives. I fondly remember a time when real Republicans stood for fiscal responsibility."

At issue on the budget is a Senate-passed provision mandating that any tax or spending measure that increases the federal deficit be offset by spending cuts or tax increases. The mandate could be lifted only with 60 votes in the 100-seat Senate. After weeks of difficult negotiations, GOP negotiators signed off on a plan that would impose such restrictions for only one year, rather than the five years the Senate approved. But they carved out $27.5 billion worth of tax cuts that could be passed this year with a simple Senate majority.

That version squeaked though the House last night, 216 to 213, with nine Republicans and all Democrats voting against it. But to win Senate approval, GOP leaders will need to win over at least two of the four balking moderates, or possibly a conservative Democrat. Each of the targets of Republican wooing roundly rejected the deal yesterday.

"The budget that is expected to be brought before the U.S. Senate this week does not meet my concerns. Therefore, I plan to vote against it," said Sen. Susan Collins (R-Maine).

David DiMartino, a spokesman for conservative Sen. Ben Nelson (D-Neb.), said leaders seeking his vote "are wasting their time."

House GOP leaders made no attempt to hide their frustration or their unwillingness to compromise further. Already bottled up in the Senate are Bush's energy package and plans for medical-liability and class-action lawsuit reform.

"For a long time the House of Representatives tried to bow and scrape and do everything it could to get along with the Senate," Hastert told reporters, adding that the House would not let the moderates "nail us down so we couldn't react to the economy" by making it harder to cut taxes.

DeLay said, "I can't believe that those three or four senators are going to bring down one of the best budgets we've ever seen over an issue that makes it difficult for Republicans to get tax relief."

Staff writer Charles Babington contributed to this report.

House Speaker J. Dennis Hastert lectured Sen. John McCain on taxes.