RICHMOND -- The United States should combat rising gas prices by cracking down on market speculators, applying pressure on oil-producing nations and taking steps to expand the nation's energy resource portfolio, former Gov. Mark Warner said Wednesday.

Warner, Virginia's Democratic U.S. Senate candidate, outlined a multifaceted plan to contain gas prices and reduce dependence on oil, further defining his stance on what could be a major issue in his contest with former Republican Gov. Jim Gilmore.

In a speech to a Richmond-area technology business group, Warner said energy "is one of the most pre-eminent issues we will face in the next quarter century."

"It's an economic issue, it's a security issue, it's an environmental issue and it's a moral issue," Warner said. "And it's time for America to take its rightful position as a leader in this field."

Warner unveiled his plan on the same day that President Bush called on Congress to lift restrictions on offshore drilling and in the Arctic National Wildlife Refuge in Alaska. Gilmore also has called for increased domestic oil production in the Alaskan refuge and offshore to help contain skyrocketing gas prices. But Warner said the approach would take years to increase fuel supplies and have only a modest effect on prices at the pump.

"Right now, my opponent's only solution is drill here, drill now," Warner said of the plan embraced by Gilmore.

Warner opposes drilling in the Alaskan wilderness refuge, as do both major-party candidates for president. Warner said he supports lifting the federal moratorium on offshore oil and natural gas exploration "to see what's there," and letting states decide whether to allow it. But Warner said oil exploration should have to meet tougher standards because of environmental concerns. He stopped short of calling for the production of oil offshore.

"But let's not fool ourselves; this is not the long-term solution," Warner told reporters after his speech at the Science Museum of Virginia.

Warner said he also would push to eliminate loopholes that have allowed speculators to drive up oil prices on overseas markets. Some experts estimate that one-third of the cost of a barrel of oil is because of speculation, Warner noted.

"That adds up to more than a dollar on a gallon of gas due to oil speculation," he said in his speech.

Warner said the U.S. also should use its trade leverage to pressure the Organization of Petroleum Exporting Countries to increase production and take action against nations and companies that collude to inflate oil prices. He called for a "market-based" approach to using the strategic petroleum reserve, and promoting telecommuting and flexible work schedules to reduce driving.

Gilmore argues that increased drilling will help reduce prices and accused Warner of latching on to "liberal theories" that won't help drivers fill their tanks.

"We need to drill here and drill now," Gilmore said in a statement released by his campaign. "When the oil speculators know the United States is serious about drilling here and taking real conservation measures, the price of gasoline will start going down."

Warner also outlined a long-term plan to diversify the nation's energy portfolio and encourage production and use of fuel-efficient and hybrid vehicles. The Democrat called for expanding tax incentives to purchase hybrid vehicles and cars with advanced battery technology. He would pay for the incentives by scaling back some of the tax breaks oil companies got in a 2005 energy bill.

"You can't have it both ways," Warner said of the oil companies. "You can't make record profits and still ask the American taxpayers to give you $17 billion out of the public till. It's not fair. It's not right."

Warner said the U.S. also should work with the petroleum industry to expand refining capacity and should significantly increase research and development of alternative energy sources, including solar, wind, "clean coal" and nuclear technologies. The tax credit for such research and development should be made permanent, he said.

Warner cited ongoing research in carbon sequestration technology at Virginia Tech as an example of initiatives that could benefit from an emphasis on research.

"Wouldn't it be great if Virginia Tech and Virginia became the leader in carbon-capture technology?" Warner said. "Wouldn't it be great if we created those jobs here?"