NEW YORK (CNNMoney.com) - The federal government may suspend its $1 billion Cash for Clunkers program after less than a week over concerns that the plan may have already burned through its funds, according to congressional sources.
A White House official said the Obama administration is assessing the situation, but added that "auto dealers and consumers should have confidence that all valid ... transactions that have taken place to-date will be honored."
The Department of Transportation, which runs the program, wants to sort out how much of the plan's funds it has already committed.
Cash for Clunkers officially launched less than a week ago.
It is set to end on Nov. 1, or whenever its $1 billion budget has been depleted.
Under the plan, vehicles purchased after July 1 will be eligible for refund vouchers worth $3,500 to $4,500 on traded-in gas guzzlers. The trade-in vehicle has to get combined city and highway fuel economy ratings of 18 miles per gallon or less.
The program, created by Congress to spur sales and help the struggling auto industry, is intended to take low-mileage cars off the road and spur new car sales for U.S. automakers.
"With this program, we are giving the auto industry a shot in the arm and struggling consumers can get rid of their gas-guzzlers and buy a more reliable, fuel-efficient vehicle," Transportation Secretary Ray LaHood said in a statement Monday.