March 5, 2012 -- Excessive speculation in the oil futures market may be costing you 15 percent or more at the gas pump and playing a "significant" role in rising gasoline prices, according to a joint letter from 68 members of Congress that ABC News has obtained.

The joint letter, which cites a recently updated report by the St. Louis Federal Reserve titled "Speculation in the Oil Market," urges immediate action by the Commodity Futures Trading Commission to install caps on the biggest traders on Wall Street, preventing them from controlling unusually large positions in the oil futures trading market.

The Reserve's report called "Speculation in the oil market," which was just updated in February 2012, concluded there are two main factors for large price swings at the gas pump.

Read the full joint letter HERE

It says "global demand shocks," such as those caused by turmoil in the Middle East, "account for the largest share of oil price fluctuations."

The report also concludes "speculation played a significant role in the oil price increase between 2004 and 2008 and its subsequent collapse. Our results support the view that the financialization process of commodity markets explains part of the recent increase in oil prices."

The Federal Reserve paper also puts a price on how much extra consumers may have had to pay at the pump during the Federal Reserve's five-year study period, saying, "speculation contributed around 15 percent to oil price increases" during the five year period analyzed.

Sen. Bernie Sanders, an Independent from Vermont, has pushed for reform on Wall Street for years. He says the Federal Reserve report is significant.

"If the St. Louis Federal Reserve, a conservative institution, is saying speculation is contributing significantly to the high price of oil and gas at the pump, then I think that is clearly what the case is," he said.

Sanders authored the joint letter and plans to send it Monday afternoon, once his staff has formally gathered the signatures of the 67 other members of Congress who have pledged to sign on.

The letter cites a failure on the part of the CFTC to enact "position limits" on those who trade in the oil futures markets. The Dodd Frank Act required the CFTC develop and enforce those limits by January 2011. More than a year later, they are not in force.

"As the cost for American people to fill their gas tanks continues to skyrocket, the CFTC continues to drag its feet on imposing strict speculation limits to eliminate, prevent, or diminish excessive oil speculation as required by the Dodd-Frank Act," they write. " Although the CFTC has adopted initial position limits, they are not strong enough and not yet in force owing to industry opposition, delays in swaps oversight and data collection. This is simply unacceptable and must change."

The letter and renewed calls for reform from Democratic leaders in Congress comes on the heels of an ABC News report from February 23, in which CFTC Commissioner Bart Chilton spoke out.

Chilton got his hands on a Wall Street research paper written by Goldman Sachs, which revealed how the firm's own research quantified specifically how much it estimated the price of oil would rise with each large speculative trade.

Using Goldman's calculations and data on the amount of speculative oil trades from the CFTC, Chilton told ABC News that if Goldman is right a Honda Civic owner is paying $7.30 extra due to a "speculative premium" every time they fill up.

Read Goldman Sachs response to Congress members' claim here

He says Ford Explorer owners would pay an addition $10.41 per fill up, while Ford F150 owners would pay $14.56.

"There aren't markets without speculation, it's the excessive speculation we are concerned about," Chilton said at the time.

A spokesperson for CFTC Chairman Gary Gensler, Stephen Adamske, noted in an email that Gensler himself did in fact vote in favor of position limits in an October 18 vote. He wrote, "the commission passed the position limits rule in October 2011, and they will become operational when we have also passed our definitional rules."

Gensler has repeatedly expressed his support for position limits on oil speculators in public hearings.

However, Michael Briggs, a spokesperson for Senator Sanders, said the CFTC refuses to enforce or implement the limits until it can gather a year's worth of financial data first, "which will not be until August at the earliest," Briggs said. "That means that the CFTC will let another summer driving season come and go before they enforce any limits on Wall Street oil speculators -- something that Sen. Sanders and the 67 other Members of Congress find unacceptable."

However, even if the CFTC relents and moves its timetable up, it still faces two federal lawsuits from Wall Street lobbyists who are trying to block any caps from ever being implemented on oil futures trading.

The International Swaps and Derivatives Association and the Securities Industry and Financial Markets Association filed the lawsuits.

They are currently petitioning a federal judge to put any implementation of the rule on hold until their legal challenges can be fully heard.

Briggs says while this issue is being litigated the Court has not issued an injunction.