Weary House lawmakers pushed toward a final vote late Tuesday night on emergency legislation to avoid the “fiscal cliff” of widespread tax increases and painful across-the-board spending cuts before financial markets reopen after the New Year’s holiday.

Passage would send the measure to President Barack Obama for his signature and hand him a political triumph less than two months after he secured re-election while campaigning for higher taxes on the wealthy.

The economic as well as political stakes were considerable. Economists have warned that without action by Congress, the tax increases and spending cuts that technically took effect with the turn of the new year at midnight could send the economy into recession.

The extraordinary late-night House vote was coming nearly 24 hours after the Senate passed the measure in the pre-dawn hours on New Year’s Day. The legislation cleared the Senate hours after Vice President Joe Biden and Senate Republican Leader Mitch McConnell, veteran negotiators, sealed a deal.

In addition to neutralizing middle class tax increases and spending cuts that technically took effect Monday at midnight, the legislation raises tax rates on incomes over $400,000 for individuals and $450,000 for couples. Remarkably, in a party that swore off tax increases two decades ago, dozens of Republicans supported the bill in both houses of Congress.

The bill would also raise the top tax rate on large estates to 40 per cent, from 35 per cent, and taxes on capital gains and dividends over $400,000 for individuals and $450,000 for couples would be taxed at 20 per cent, up from 15 per cent.

The bill would also prevent an expiration of extended unemployment benefits for an estimated two million jobless, renew tax breaks for businesses and renewable energy purposes, block a 27 per cent cut in fees for doctors who treat elderly Medicare patients, stop a $900 pay increase for lawmakers from taking effect in March and head off a threatened spike in milk prices.

It would stop $24 billion in spending cuts set to take effect over the next two months, although only about half of that total would be offset with spending reductions elsewhere in the budget.

Even with enactment of the legislation, taxes are on the rise for millions.

A 2 percentage point temporary cut in the Social Security payroll tax, originally enacted two years ago to stimulate the economy, expired with the end of 2012. Neither Obama nor Republicans made a significant effort to extend it.

The fiscal cliff measure had cleared the Senate on a lopsided pre-dawn New Year’s vote of 89-8, and House Republicans spent much of the day struggling to escape a political corner they found themselves in.

“I personally hate it,” Rep. John Campbell of California, said of the measure, giving voice to the concern of many Republicans that it did little or nothing to cut spending.

Majority Leader Eric Cantor, the No. 2 House Republican, told reporters at one point, “I do not support the bill. We are looking, though, for the best path forward.”

Within hours, Republicans abandoned demands to add spending cuts to the bill and agreed to a simple yes-or-no vote on the Senate-passed bill.

They feared that otherwise the Senate would refuse to consider any alterations, sending the bill into limbo and saddling Republicans with the blame for a whopping middle class tax increase. One Senate Democratic leadership aide said Majority Leader Harry Reid would “absolutely not take up the bill” if the House changed it. The aide spoke on condition of anonymity, citing a requirement to keep internal deliberations private.

If the House failed to pass the Senate bill it would mean that any fiscal deal would have to start all over when a new Congress, with dozens of new members, is seated Thursday. And any change in the legislation would require the Senate to re-pass the measure before it could go to Obama for his signature.

Despite Cantor’s remarks, Speaker John Boehner took no public position on the bill as he sought to negotiate a conclusion to the final crisis of a two-year term full of them.

Republicans did their best to minimize the tax increases in the measure.

Rep. David Dreier of California, in the final days of a 32-year-career in Congress, said the legislation was “not the grand bargain we’d hoped for” to reduce federal deficits. “But it is an essential bridge to what I hope will be a comprehensive and long-term solution. It will bring us back from the edge of the fiscal cliff and implement tax cuts for 99% of taxpayers.”

Declared Rep. Marcy Kaptur, an Ohio Democrat- “This is a great victory for the middle class, whose taxes will not go up tomorrow.”

“That is what we expect. That is what the American people deserve,” she said.

The non-partisan Congressional Budget Office said the measure would add nearly $4 trillion over a decade to federal deficits, a calculation that assumed taxes would otherwise have risen on taxpayers at all income levels. There was little or no evident concern among Republicans on that point, presumably because of their belief that tax cuts pay for themselves by expanding economic growth and do not cause deficits to rise.

The relative paucity of spending cuts was a sticking point with many House Republicans. Among other items, the extension of unemployment benefits costs $30 billion, and is not offset by savings elsewhere.

For all the struggle involved in the legislation, even its passage would merely clear the way for another round of controversy almost as soon as the new Congress convenes.

With the Treasury expected to need an expansion in borrowing authority by early spring, and funding authority for most government programs set to expire in late March, Republicans have made it clear they intend to use those events as leverage with the administration to win savings from the Medicare health care program for the elderly and other government benefit programs.

Mr. McConnell said as much moments before the 2 a.m. Tuesday vote in the Senate two hours after the advertised “cliff” deadline.

“We’ve taken care of the revenue side of this debate. Now it’s time to get serious about reducing Washington’s out-of-control spending,” he said. “That’s a debate the American people want. It’s the debate we’ll have next. And it’s a debate Republicans are ready for.”

Mr. Obama, who had campaigned for re-election on the promise of protecting households making under $250,000 a year from a tax increase, praised the agreement after the Senate’s vote. Some liberal Democrats were disappointed that the White House did not stick to a harder line in negotiations, considering that Obama no longer faces re-election.

“While neither Democrats nor Republicans got everything they wanted, this agreement is the right thing to do for our country and the House should pass it without delay,” Mr. Obama said in a statement. “This agreement will also grow the economy and shrink our deficits in a balanced way by investing in our middle class, and by asking the wealthy to pay a little more.”

The “fiscal cliff” came about because tax rate cuts enacted in 2001 and 2003 during President George W. Bush’s administration were set to expire at the end of the year. The threatened across-the-board reductions in government spending, which would slice money out of everything from social programs to the military, were put in place last year as an incentive to both parties to find ways to cut spending. That solution grew out of the two parties’ inability in 2011 to agree to a grand bargain that would have taken a big bite out of the deficit which has averaged about $1 trillion a year.

If Mr. Obama and Congress failed to act, about $536 billion in tax increases, touching nearly all American workers, and about $110 billion in spending cuts, about 8 percent of the annual budgets for most federal departments, were scheduled to start going into effect beginning in January.