WASHINGTON — The House of Representatives voted to provide an emergency $2 billion for the “cash for clunkers” program on Friday, and the White House declared the program very much alive, even though car buyers appear to have already snapped up the $1 billion that Congress originally appropriated.

The House shoved other business out of the way on its last day before the August recess to rush through a measure to address the cash shortage of the car program. The vote was 316 to 109, with significant support from Republicans as well as Democrats.

The Senate, which will be in session next week, will take up the program then. A spirited debate is likely, as some senators have said they will use the opportunity to push for tougher fuel-efficiency requirements. If the Senate does not go along with the House’s version, the House might have to return to work on a compromise.

Minutes after the House vote, President Obama praised the legislators for moving quickly. “We’re already seeing a dramatic increase in showroom traffic,” he said, adding that the program helps to reduce air pollution while helping car buyers.

The sudden legislative action was prompted by the overwhelming response to the program, formally known as the Car Allowance Rebate System, which its backers say has helped not only car buyers but the struggling automobile industry.

Earlier Friday, Robert Gibbs, the chief White House spokesman, offered assurances that the administration was looking for ways to continue the popular new program, which offers $3,500 to $4,500 for people who trade in an old car for a new one with higher fuel economy.

“If you were planning on going to buy a car this weekend using this program, the program continues to run,” he said. “If you meet the requirements of the program, the certificates will be honored.”

Mr. Gibbs declined to say how long the program could continue without an infusion of funds.

The $2 billion infusion approved by the House would come from money already set aside for an Energy Department’s loan guarantee program and give it to the rebate program.

“Consumers have spoken with their wallets,” Representative David R. Obey, Democrat of Wisconsin of chairman of the House Appropriations Committee, said in urging quick passage.

The panel’s ranking Republican, Jerry Lewis of California, complained that Democrats, who have a 256-to-178 majority in the House, were rushing the measure through with too little thought, — “shoveling another $2 billion out the door,” in his words.

But in the end, there was enough support from Republican in states that rely on the auto industry to push the measure through. Over all, 239 Democrats and 77 Republicans voted in favor, while 14 Democrats and 95 Republicans voted against the measure.

Before the House vote, Senator Carl Levin, Democrat of Michigan, said it was not clear how long funds for the program would last, “so people should go to their car dealers now if they want to take advantage of the program.

Some lawmakers succumbed to the temptation to use car-and-road metaphors.

Representative Steve Israel, Democrat of New York, said Americans had taken the program “for a test drive” and liked it. He predicted that $2 billion would be enough until Congress returns in September, but he urged quick Congressional action to minimize public alarm and confusion. And Representative Candice Miller, Republican of Michigan, said the country may be about to turn a corner on its way back to prosperity. “This road is paved by the ‘cars for clunkers’ program,” she said.

The program has proved a boon to the auto industry as it struggles to regain its footing, drawing crowds of customers to some showrooms as dealers aggressively promoted the rebates in ads over the last week.

There was wide support for an additional appropriation for “cash for clunkers,” with members of the Michigan delegation in the forefront. But support was not unanimous and some members of Congress thought the requirements should be tightened.

Senators Dianne Feinstein, a California Democrat, and Susan Collins, a Maine Republican, said in a joint statement that “we will insist that any extension of the program requires that the minimum fuel economy improvement for newly purchased vehicles be at least two miles per gallon higher than it is under the enacted Clunkers program.” For cars, the current minimum improvement is five miles a gallon. And, they said, to help low-income car owners take part, they would include vouchers for fuel-efficient used vehicles.

But Representative John Dingell, a Michigan Democrat who is the longest-serving member of the House, said this is no time to get bogged down trying to change a program that works. In a telephone interview on Friday afternoon, he called the program “one of the most successful parts of our effort to reinvigorate and restart the American economy,” and a boon to the environment because it gets “old, dirty, polluting cars” off the roads.

Representative Ed Markey of Massachusetts, one of the authors of the original bill, also called for a simple extension. He declared Thursday night, “Cash for Clunkers may have run out of cash, but America’s consumers haven’t run out of clunkers.” He said it should be extended to cover 1 million vehicles, about four times the number covered so far.

Mr. Markey said so far participants in the program were getting a 69 percent improvement in fuel economy, with the trade-ins being mostly sport utility vehicles, trucks and vans with over 100,000 miles, being replaced with new passenger cars.

Others were outright opposed; Representative Jeb Hensarling, a Texas Republican who sits on the House Budget Committee, called the program “another example of the government picking winners and losers.” The program, he said, “enshrines us as a bailout nation.”

In his district in East Texas, he said that Pilgrim’s Pride, a poultry producer, had recently filed for bankruptcy. “Where’s their ‘cash for cluckers’ program?” he asked, liking his line enough to repeat it on the House floor on Friday.Opposition to the original legislation calling for $4 billion in credits had prompted proponents to reduce the amount to $1 billion.

Meanwhile, some consumers were upset during the past week when mileage estimates were revised, disqualifying some who thought they were eligible. A Web site, NoCashForClunkers.com, has launched an online petition asking Congress to loosen the standards in any emergency legislation so more drivers can qualify.

Under the program, a buyer who picked a car with a mileage improvement of more than four miles per gallon but less than 10 were eligible for $3,500; a buyer whose new vehicle was rated 10 miles per gallon or better than the old one was eligible for $4,500.

Until the cash-for-clunkers program began, the auto industry had been on track for annual sales of about 10 million units, down from the peak of about 16 million units a year.