Republican leaders on Capitol Hill are vowing to revive a sweeping budget-cut bill despite an embarrassing setback this week. But they won't have an easy time of it considering divisions within the GOP and a revolt by party moderates over cuts to social programs like food stamps, Medicaid, and student loans.

GOP leaders scuttled plans for a vote on the $51 billion budget cut Thursday, saying they were short of votes and were worried about colleagues slipping home to their districts for Veterans Day events.

The episode marked a setback for Republicans who had hoped to use the budget debate to burnish their deficit-cutting credentials with the public and their core political supporters, many of whom are disappointed with their party's performance on spending.

The decision by GOP leaders came despite a big concession to moderates Wednesday, when the leaders dropped provisions to open the Arctic National Wildlife Refuge, commonly called ANWR, to oil and gas exploration, as well as a plan to let states lift a moratorium on oil drilling off the Atlantic and Pacific coasts.

But moderates countered that the spending cuts in the House budget plan were a separate issue from Arctic drilling. The cuts were too severe, moderates argued, especially when compared with a significantly milder Senate budget plan that passed last week.

Democrats mounted a furious attack on the GOP budget plan for its cuts to social programs and pounded home the message that the overall GOP plan would increase the deficit when coupled with a subsequent tax cut bill.

"The Republican Congress is about to slash more than $50 billion from investments in our children's future in health care and education," said Rep. Rahm Emanuel of Illinois, chairman of the campaign arm for House Democrats. "And yet, because of Republican priorities, they are going to actually add $20 billion to our budget deficit. ... Only in a Republican Congress."

Republican leaders said the postponement of the vote was simply a modest setback and that the budget effort would get back on track next week.

Acting House Majority Leader Roy Blunt, R-Mo., said the leadership was short a "handful" of votes.

"The members aren't used to dealing with these mandatory programs," he said. "They're not used to pushing back when the (Democratic) side suggests that the savings are deep cuts in social programs."

"Democrats were united and made those issues too hot to handle for Republicans," said Minority Leader Nancy Pelosi, D-Calif.

GOP leaders are willing to make more changes to the bill, Blunt said, but they risk a backlash from conservatives if the level of budget savings drops below a $50 billion figure promised by House Speaker Dennis Hastert, R-Ill.

"I think we'll have the votes next week," Blunt said.

Others are not so sure, noting that moderate opponents to the bill seemed unusually resolute.

At a news conference with a number of GOP moderates, Rep. Wayne Gilchrest, R-Md., said the budget bill "is still a work in progress" and he still opposes some of its provisions. But he acknowledged that resistance to ANWR drilling unified the GOP moderates in challenging the leadership.

"One thread that held us together on this was ANWR. We knew if we could hold together on ANWR all these other provisions would be subject to much closer scrutiny," said Gilchrest.

The overall bill is a Republican priority. The Senate last week passed a milder version to curb the automatic growth of federal spending by $35 billion through the end of the decade.

The House plan cuts more deeply across a broader range of social services. Republican leaders say the effects will be modest to programs like the Medicaid health system for the poor and disabled, even though beneficiaries would face increased copayments and the likely loss of some benefits.

The House convened Thursday and almost immediately went into a lengthy recess as GOP leaders, including Blunt and Hastert, worked to assemble support for the bill. In meetings with rank-and-file lawmakers, the leaders signaled a willingness to ease cuts to the Medicaid program.

The resistance from GOP moderates was a setback for the reshuffled House leadership. Blunt assumed the majority leader's post after Tom DeLay, R-Texas, was forced to step aside in September because of his indictment on criminal conspiracy and money laundering charges.

White House press secretary Scott McClellan said Thursday the president was pleased that Congress was moving forward with deficit-reduction packages even though he still strongly supports opening a portion of the Alaska wildlife refuge to oil exploration.