A US Senate panel has approved a plan to increase fuel efficiency standards to an average of 35 miles per (US) gallon by 2020.

According to The Associated Press (AP), the Senate Commerce, Science and Transportation Committee approved the measure, which would raise the nationwide fleet fuel economy average by about 40% from current levels of 25 mpg for cars and trucks. The bill, approved on a voice vote, would also increase standards by 4% a year from 2020 to 2030.

“This is not a perfect bill, but I think we have reached a stage where most parties would say this is fair,” AP quoted Senator Daniel Inouye, an Hawaii Democrat and the committee chairman, as saying. He reportedly added the bill would be considered before the full Senate in June.

AP said this was lawmakers’ first step in demanding more efficient vehicles from automakers amid concerns about global warming and the nation’s dependence on imported oil. Petrol prices have leapt in recent weeks to a record nationwide average of $US3.07 a gallon, or nearly 20 cents higher than two weeks earlier, according to the Lundberg Survey, the news agency noted.

Prices have topped the $4 mark in some states and the issue has again been a key item on national TV news bulletins

AP said US fuel economy standards have made little progress in the past 20 years – passenger cars are required to meet a fleetwide average of 27.5 miles per gallon while SUVs, pickup trucks and vans must meet a standard of 22.2 mpg.

Lawmakers were reported to have said the bill was a compromise that would likely face a number of changes on the Senate floor – two senators said they had concerns about how it might affect trucks and its overall fairness.

Another said he would aim for a fleet increase of up to 40mpg by 2020, while one-time presidential hopeful John Kerry wants to guarantee 31mpg by 2015 and 35mpg by 2020.

AP said the committee also approved by voice vote a proposal to create federal criminal penalties for price gouging at the fuel pump if the president declares an emergency because of high energy prices.

Republicans reportedly opposed the plan, saying it included an arbitrary definition of price gouging.

The Associated Press said that, under the broader bill, large work trucks and tractor trailers would have to meet fuel economy requirements for the first time but the timeline was unclear because any requirements would first require a federal study.

Other provisions include letting the National Highway Traffic Safety Administration reform passenger car standards to take into account a vehicle’s dimensions and requiring the government to purchase more fuel-efficient fleet vehicles, the report said.

According to AP, the Alliance of Automobile Manufacturers, which includes Detroit’s automakers and Toyota, has said the proposal would be unattainable and threaten jobs.

Alan Reuther, the United Auto Workers‘ legislative director, reportedly said in a letter to Inouye that it would force manufacturers “to close more facilities, destroying tens of thousands of additional jobs and undermining the economic base of communities across this country.”

Environmentalists told the news agency they were concerned that the proposal was weaker than one offered by President Bush, which would set a goal of a 4% annual increase while expanding use of alternative fuels.

“When you look at all the loopholes in this 35 mpg bill, it kind of looks like Swiss cheese,” David Friedman of the Union of Concerned Scientists told the Associated Press.