The U.S. House of Representatives approved legislation Tuesday aimed at stimulating auto sales by providing cash vouchers to consumers to trade in gas-guzzling cars for newer, more efficient models.

The 298-119 vote culminates months of wrangling among lawmakers over the details of a so-called "cash for clunkers" program, pushed mainly by Democrats and President Barack Obama. Most members voting "yes" were Democrats, while all but a few of the "no" votes came from Republicans.

The legislation aims to halt a steep slide in auto sales. Proponents pointed to a program in Germany credited with spurring a double-digit spike in car purchases there.

Rep. Sandy Levin, D-Mich., said the U.S. government's efforts to restructure the auto industry, which is costing tens of billions of dollars, "won't work if there isn't work on the demand side."

The legislation, which still must be passed by the Senate, faces hurdles, including questions about where to find the money for the one-year, $4 billion program. Some lawmakers have suggested the money could come from the economic-stimulus package passed earlier this year.

The House bill, authored by Rep. Betty Sutton, D-Ohio, would authorize the administration to provide cash vouchers of as much as $4,500 to consumers who trade in older vehicles and then lease or purchase a newer, more energy-efficient one. It would require the older vehicle to have a fuel economy of 18 miles per gallon or less and the newer vehicle to get at least 22 mpg. The voucher would be worth $3,500 if the newer vehicle achieved a 4 mpg increase in fuel economy. If the mileage of the new car was at least 10 mpg higher than the older vehicle, the voucher would be worth $4,500.

The older vehicles would be dismantled.

Vouchers would also be issued for light-duty and large trucks. The program would be designed to replace 1 million vehicles.

"I believe it hits the trifecta," said Rep. Henry Waxman, D-Calif., chairman of the House Energy and Commerce Committee. "It's good for the economy, it's good for the consumers, and it's good for the environment."

But some Republicans criticized the legislation as a government handout to the auto industry, citing the tens of billions of dollars provided to General Motors Corp. (GMGMQ) and Chrysler LLC.

"It's defying the laws of economics and saying we can manufacture enough demand to keep the auto industry afloat," said Rep. Jeff Flake, R-Ariz.

He also questioned where Congress would find the money for the program.

-By Josh Mitchell, Dow Jones Newswires; 202-862-6637; joshua.mitchell@dowjones.com