Updated

Republicans are not giving up the fight against the sweeping health care legislation making its way toward a final vote in the Senate, vowing to do everything they can to sideline the package even though Democrats appear to have the votes they need to pass it.

"This bill is a monstrosity," Senate Republican Leader Mitch McConnell said. "This is not renaming the post office. Make no mistake -- this bill will reshape our nation and our lives."

He and other Republicans lambasted the bill for Medicare cuts that the Congressional Budget Office said totaled more than $470 billion over a decade, and what McConnell called "massive tax increases" at a time when unemployment is at 10 percent.

Speaking on "Fox News Sunday," Sen. John McCain, R-Ariz., said his party probably can't prevent its passage in the Senate, but said he and his colleagues would fight the bill all the same.

"What we can do is continue winning the battle of American public opinion," he said. "We'll fight the good fight. We will fight until the last vote."

Sen. John Cornyn, R-Texas, called the bill "fatally flawed." With senators set to resume debate Sunday afternoon, Republicans note the CBO concluded that under the bill, "federal outlays for health care would increase during the 2010-2019 period, as would the federal budgetary commitment to health care."

But Republicans face an even tougher challenge in disrupting the health care reform momentum now that Senate Majority Leader Harry Reid has won over Sen. Ben Nelson, D-Neb., who had been the Democrats' only known holdout.

To get Nelson's vote, Reid agreed to a series of concessions on abortion and other issues demanded by Nelson and then informed President Obama of the agreement as the president flew home from climate talks in Copenhagen.

Obama welcomed the breakthrough, saying in a statement at the White House, "After a nearly centurylong struggle, we are on the cusp of making health care reform a reality in the United States of America."

The CBO said the Senate bill would extend coverage to more than 30 million Americans who lack it. It also imposes new regulations to curb abuses of the insurance industry, and the president noted one last-minute addition would impose penalties on companies that "arbitrarily jack up prices" in advance of the legislation taking effect.

CBO analysts also said the legislation would cut federal deficits by $132 billion over 10 years and possibly much more in the subsequent decade.

At its core, the legislation would create a new insurance exchange where consumers could shop for affordable coverage that complied with new federal guidelines. Most Americans would be required to purchase insurance, with federal subsidies available to help defray the cost for lower and middle income individuals and families.

In a concession to Nelson and other moderates, the bill lacks a government-run insurance option of the type that House Democrats inserted into theirs. In a final defeat for liberals, a proposed Medicare expansion was also jettisoned in the past several days as Reid and the White House maneuvered for 60 votes.

The Associated Press contributed to this report.