Pelosi (D-Calif.) announced to Democratic leaders Tuesday night that she has written a letter to President Bush, urging him to release a “small” amount of oil from the government stockpile to increase supply and decrease prices, a leadership aide said.

"These are the kind of circumstances, in addition to national security, in which utilization of the Strategic Petroleum Reserve is more than justified," Pelosi wrote in the letter, dated Tuesday.

The reserve comprises a series of Gulf Coast salt caverns that house the largest emergency oil stockpile in the world. It currently holds 706 million barrels, about 97 percent of the reserve’s 727 million barrel capacity. That’s the most the reserve has ever held and would replace foreign supplies for about 58 days.

It is not clear what impact a release would have on current prices. The U.S. uses about 20 million barrels of oil a day.

Pelosi’s letter noted that a release at the time of the start of the first Gulf War in 1991 brought prices down $8 a barrel. When President Clinton ordered a swap in 2000 to lower prices, she wrote, prices dropped 34 percent, to a little more than $20 a barrel.

The most recent drawdown, after Hurricane Katrina in 2005, lowered prices by about $5 a barrel, she said.

The reserve’s previous record of 700 million barrels was reached shortly before that post-Katrina drawdown.

Earlier this year, congressional Democrats scored their biggest success over Bush on energy when they passed legislation freezing the size of the reserve by a veto-proof majority. It was also supported by the three remaining presidential candidates at the time.

Bush opposed the idea, saying the 70,000 barrels a day being pumped into the reserve was too small to make a difference in prices. But he later relented. He signed the bill and deliveries stopped.

Pelosi’s is not the only proposal related to the reserve. Rep. Nick Lampson (D-Texas) has introduced a bill to take out more expensive “light” crude, and replace it with cheaper “sour” crude. He would use the difference in price to fund energy research.

The oil stockpile is designed to prevent an economically threatening disruption in oil supplies, according to the Department of Energy, which runs the reserve.

The stockpile has grown larger under President Bush, who has made it bigger and filled it fuller than ever before.

The 2005 energy bill ordered the Department of Energy to expand the capacity of the reserve to 1 billion barrels.

Bush went further in January 2007, announcing plans to double the size of the reserve to 1.5 billion barrels.