Washington (CNN) -- In a dramatic twist played out on the floor of the Senate, Majority Leader Harry Reid conceded Thursday night he lacked the votes to bring up a $1.1 trillion spending bill designed to fund the federal government for the rest of the current fiscal year.

Reid, D-Nevada, accused Republicans of withdrawing previously pledged support for the bill, and said he would work with the Senate Republican leader to draft a short-term spending measure that would keep the government running beyond Saturday, when the current spending authorization resolution expires.

"A number of Republican senators told me they'd like to see this pass, but they can't support it," Reid said, adding that nine GOP senators who previously told him they backed the bill had changed their stance.

The shift announced by Reid culminated a Republican effort to kill the spending bill and likely put off major spending decisions for the rest of fiscal year 2011 until a more conservative Congress convenes in January.

The House of Representatives has passed a resolution that authorizes spending at the same level as last year until September 30, when fiscal year 2011 ends. The Senate spending bill, drafted by Democrats and Republicans on the Appropriations Committee, was a more flexible appropriation measure that would have given government departments more leeway in how they spend their budgets.

Earlier Thursday, Defense Secretary Robert Gates called for the Senate to pass the spending bill because it would allow his department to meet changing priorities in the current year.

Republicans, however, complained the Senate bill would have continued excessive government spending including $8 billion in earmarks, or provisions requested by individual legislators.

"Once the new Congress is sworn in, we'll have a chance to pass a less expensive bill free of this kind of wasteful spending," Senate Minority Leader Mitch McConnell, R-Kentucky, said Thursday. "Until then we need to step back and respect the will of the voters."

In addition, all 12 Republican senators-elect sent a letter to McConnell and Reid, saying they are "united in opposition to the current effort in Congress to pass yet another unseen bill, loaded with wasteful spending."

Two Republican senators, John McCain of Arizona and newcomer Mark Kirk of Illinois, proclaimed victory on the Senate floor shortly after Reid's announcement, drawing angry responses from Democrats.

Sen. Claire McCaskill, D-Missouri, accused McConnell of unfairly characterizing the spending bill as a Democratic proposal when it was compiled by senators from both parties on the Appropriations Committee. McCaskill also criticized McCain and Kirk for their victory proclamation.

"If we want to work together, we've got to stop trying to score cheap political points," McCaskill said, adding: "We probably both (Democrats and Republicans) need to work a little harder at trying not to score cheap political points, as the Minority Leader (McConnell) did on the floor a few minutes ago."

Sen. Dick Durbin, D-Illinois, earlier called the GOP hypocritical, noting that a large number of the earmarks in the bill had been previously requested by Republican members. Durbin also said the legislation had been set at $1.1 trillion in order to satisfy McConnell's demands.

This is "the very same number" the Republican leader insisted upon, Durbin said.

Reid said, if you looked up hypocrisy in the dictionary, "under that would be people who ask for earmarks but vote against" in the final bill. Republicans "hate to vote for them but love to get them," he added.

Reid framed the dispute over earmarks as one tied to the government's separation of powers, and said he didn't understand why self-proclaimed conservatives would oppose the practice.

Taking away earmarks is "a way for the executive branch of government to steal" congressional powers, he said. "I do not want to give up more power to the White House, whether it's George Bush or Barack Obama."

The rise of the conservative Tea Party movement influenced what happened on the issue. South Carolina GOP Sen. Jim DeMint, a leading voice of the Tea Party movement, had threatened to force the almost 2,000-page bill to be read out loud before it could be debated.

Reading the bill was expected to take more than two days, endangering progress on other issues as the lame-duck session headed to conclusion.

Spending authorization bills are necessary to keep the government running, and the current resolution expires on December 18. Both chambers will have to approve a common approach to prevent the government from shutting down after that date.

President Barack Obama had requested almost $1.14 trillion in spending for the 2011 fiscal year, which began October 1 and ends on September 30, 2011.

The resolution passed by the House is $1.089 trillion -- $45.9 billion less, according to House Appropriations Committee Chairman David Obey, D-Wisconsin.

CNN's Alan Silverleib, Tom Cohen and Ted Barrett contributed to this report