WASHINGTON — The House on Tuesday approved a “cash for clunkers” bill that aims to boost new auto sales by allowing consumers to turn in gas-guzzling cars and trucks for vouchers worth up to $4,500 toward more fuel-efficient vehicles.

Supporters pushed for the measure to stimulate car sales and increase the fleet of fuel-efficient vehicles on the nation’s highways. The auto industry has sought the incentives after months of poor auto sales. In May, overall sales were 34 percent lower than a year ago.

Opponents said the vehicle scrappage bill, which passed on a 298-119 vote, failed to include incentives for used vehicles and represented an artificial incentive for the industry.

Under the House bill, dealers participating in the program would receive an electronic government voucher for the trade-in to apply to the purchase or lease of a qualifying vehicle.

Car owners could get a voucher worth $3,500 if they traded in a vehicle getting 18 miles per gallon or less for one getting at least 22 miles per gallon. The value of the voucher would grow to $4,500 if the mileage of the new car is 10 mpg higher than the old vehicle. Miles per gallon figures are listed on the window sticker.

Owners of sport utility vehicles, pickup trucks or minivans that get 18 mpg or less could receive a voucher for $3,500 if their new truck or SUV is at least 2 mpg higher than their old vehicle. The voucher would increase to $4,500 if the mileage of the new truck or SUV is at least 5 mpg higher than the older vehicle. Consumers could also receive vouchers for leased vehicles.

The bill would direct dealers to ensure that the older vehicles are crushed or shredded to get the clunkers off the road. It was intended to help replace older vehicles — built in model year 1984 or later — and would not make financial sense for consumers owning an older car with a trade-in value greater than $3,500 or $4,500.

A group of senators led by California Democrat Dianne Feinstein were pushing an alternative version that would require consumers to trade up for more fuel-efficient cars and trucks to qualify.

A passenger car owner’s trade-in would need to get 17 mpg or less to qualify and only new passenger cars getting at least 24 mpg would be eligible.

Owners could receive a $2,500 voucher for a new car that gets at least 7 mpg more than their old car. The voucher would increase to $3,500 for new cars with a 10 mpg improvement and $4,500 for new cars with a 13 mpg increase in fuel efficiency.