WASHINGTON – As the Senate wrestles in slow motion over energy legislation this week, the White House warned lawmakers the president would oppose any bill that fails to allow oil drilling in Alaska’s Arctic National Wildlife Refuge. It also predicted that efforts to require greater fuel efficiency for passenger vehicles would result in “thousands of additional passenger fatalities and injuries” by requiring smaller and lighter cars.

Despite the warning, Maine’s two Republican senators, Olympia Snowe and Susan Collins, stand firm in their high-profile efforts to protect the Arctic wilderness from commercial development. They also plan to vote in favor of increased fuel efficiency on sport utility vehicles – one of Detroit’s most popular products in recent years.

The Democratic version of the energy bill now being debated endorses both positions, which have ignited a hostile outcry from Republican leaders who share President Bush’s view that opening up ANWR is key to lifting U.S. dependence on foreign oil and that a mandated increase in fuel economy would result in unsafe and more expensive cars for the American consumer.

The House approved its version of an energy agenda last summer largely along party lines. It includes many of the measures sought by the Bush administration such as opening up the Arctic refuge and approving nearly $30 billion in tax breaks for fossil fuel development.

Last spring, Snowe first introduced bipartisan legislation to close the SUV “loophole.” Co-sponsored by Sen. Dianne Feinstein, D-Calif., the measure calls for redefining sport utility vehicles as passenger vehicles rather than light trucks. By doing so, it would require that the average gas mileage of SUVs, vans and light trucks be raised from 20.7 miles per gallon to 27.5 mpg by 2007 – the same gas mileage required of other vehicles such as sedans and station wagons.

“The fastest, cheapest, and cleanest step we could take toward reducing our nation’s dependence on foreign oil would be to improve the fuel efficiency of America’s auto fleet – and particularly our biggest gas guzzlers – SUVs and minivans,” Snowe said last month.

Linking the proposal to her opposition to ANWR drilling, she added: “The U.S. Geological Survey estimates the region [ANWR] would produce approximately the same amount of oil – 700,000 to 1.2 million barrels daily – that we could save by closing the ‘SUV loophole.'”

Snowe’s proposal received early support inside the Senate and a warm reception from environmental lobbying groups, but several more ambitious proposals to increase the gas mileage of all passenger vehicles have since taken the limelight. One, sponsored by Sen. John Kerry, D-Mass., would require raising corporate average fuel economy, or CAFE, standards to 35 mpg by 2013. A second proposal, introduced by Sen. John McCain, R-Ariz., would boost CAFE standards to 36 mpg by 2016.

Still, Snowe is playing an active role behind the scenes to hammer out a compromise on the varying measures.

“A breakthrough is expected as early” as today, according to Snowe spokesman Dave Lackey.

Meanwhile, environmental groups have heaped praise on Collins and Snowe for their position on protecting ANWR from oil drilling. On Tuesday, Americans for Alaska celebrated the two Maine lawmakers, along with two other Republican senators, in a full-page advertisement in the conservative newspaper The Washington Times.

“Only the Senate can protect the Arctic Refuge,” the ad read. “Only great senators would.”

Both Snowe and Collins also support a number of Senate measures that they say would allow for $16 billion in tax incentives, about half of which would go to the development of renewable energy sources such as wind, solar, biomass and geothermal sources and less toward fossil fuels. The House energy bill seeks to provide nearly twice the amount in tax breaks, with the vast majority going to coal, oil, gas and nuclear energy production.

Snowe, who helped craft many of the tax incentives as a member of the Senate Finance Committee, said the support for renewable energy “will not only benefit the environment, but also reduce U.S. dependence on foreign oil.”

Although supportive of the renewable measures, Collins would like to see them go further.