WASHINGTON — The House on Thursday prepared to vote on a bipartisan budget accord that should calm the spending battles that have paralyzed Congress for nearly three years. A deal could also marginalize the Republicans’ most conservative members, who remain implacably opposed to it.
The spending-and-tax legislation, with the backing of its conservative architect, Representative Paul D. Ryan of Wisconsin, Republican leaders and Republican defense hawks, is expected to pass Thursday evening with bipartisan support. But conservative activists and some liberal groups are mustering opposition, raising the level of drama.
House Speaker John A. Boehner of Ohio pointedly accused some conservative groups of rallying grass-roots opposition to raise money and bolster their own stature.
“They’re using our members and they’re using the American people for their own goals,” he said, speaking openly about what some lawmakers have long talked about privately. “This is ridiculous.”
The deal would reverse many of the across-the-board spending cuts, known as sequestration, that went into effect in March and were set to deepen next month. Spending on defense and domestic programs would rise from the $ 967 billion level expected this fiscal year to $ 1.012 trillion, then inch up to $ 1.014 trillion in the fiscal year that begins in October.
But over 10 years, deficits would go down slightly, thanks to higher airline ticket fees, larger worker contributions to federal retirement plans, slower growth in military pensions, and a two-year extension next decade of a 2 percent cut to Medicare health care provider payments.
The legislation, worked out by Mr. Ryan, chairman of the House Budget Committee, and Senator Patty Murray of Washington, chairwoman of the Senate Budget Committee, has the backing of many Republican and Democratic leaders, as well as most members of the House Armed Services Committee, the House Appropriations Committee and Mr. Ryan’s budget panel.
That should be enough to assure passage over the strident opposition of Tea Party conservatives and outside conservative groups that have vowed to kill the deal.
“We feel very good about where we are with our members,” Mr. Ryan said.
But top Republicans are divided on it. Mr. Boehner supports it. Senator Mitch McConnell of Kentucky, the Senate Republican leader, does not.
Two potential rivals for the 2016 presidential nomination, Senators Marco Rubio of Florida and Rand Paul of Kentucky, are also opposed.
Senator Jeff Sessions of Alabama, the ranking Republican on the Senate Budget Committee, declared his opposition Wednesday night.
“Much of the spending increase in this deal has been justified by increased fees and new revenue,” Mr. Sessions said. “In other words: it’s a fee increase to fuel a spending increase — rather than reducing deficits.”
Some conservatives feel betrayed, as they often have since Republicans took control of the House in 2011. Representative Jim Jordan, Republican of Ohio, said the entire House Republican conference agreed in the spring that spending levels exacted by the sequestration cuts would not be alleviated unless Congress and the White House could strike an accord to control long-term drivers of the federal debt, Medicare, Medicaid and Social Security.
Representative Tim Huelskamp, Republican of Kansas, said that most of the deficit reduction in the Ryan-Murray legislation “could be in Hillary’s second term,” a nod to Hillary Clinton’s expected presidential bid and a measure of conservative demoralization.
The deal would not address the government’s statutory debt limit, which Treasury Secretary Jacob J. Lew has said will have to be lifted by March to avoid a devastating default. But Representative Raúl Labrador, Republican of Idaho, said that Republicans “should just cave” on that too, “because that’s what Republicans do.”