House Speaker Nancy Pelosi on Thursday called on the Bush administration to stop adding oil to the Strategic Petroleum Reserve, as Republicans and Democrats blamed each other for high gasoline prices.

“The longer the president delays action the more the American people will pay at the pump and the more it will be a drag on an already lagging economy,’’ Pelosi, D-Calif., said, estimating that presidential action could lower retail gasoline prices by five to 10 cents a gallon.

Her move came after days of sniping by Republicans, who have derided the recent surge in gas prices to more than $4 a gallon in some areas as the “Pelosi premium,” citing the Speaker’s promise in the 2006 elections to lower fuel prices. Democrats had blamed Republicans for the high prices at the time.

Pelosi said halting shipments to the reserve, which contains 701.3 million barrels of oil and is some 97 percent full, would have more of an impact on prices than a suspension of the federal gas tax, as proposed by Sen. John McCain of Arizona, the presumptive Republican presidential nominee.

McCain last week unveiled his proposal for a moratorium on the 18.4-cent-a-gallon gasoline tax and 24.4-cent-a-gallon diesel tax as part of a broader economic plan.

The Speaker told reporters that the gas tax cut might not be passed along to consumers, while suspending deliveries to the national reserve would inject immediate supply into the oil market, producing quick cuts in the price of oil on the world market.

House Minority Leader John A. Boehner , R-Ohio, said he would be open to supporting Pelosi’s latest proposal.

“I think it’s an idea worthy of discussion,’’ he said.

Boehner said McCain’s proposal also was worthy of consideration and disputed the idea that prices at the pump would not fall. “My guess is if it were repealed prices would fall 18 cents. Why wouldn’t it? I’m for anything that cuts taxes on the American people,’’ he said.