US Senate majority leader Bill Frist and House Speaker Dennis Hastert urged Bush to ensure the enforcement of laws banning price fixing and other anti-competitive practices in an open letter.
"We respectfully request that you direct the Attorney-General and the Chairman of the Federal Trade Commission to investigate any potential collusion, price fixing or gouging in the sale or distribution of gasoline, petroleum distillates or ethanol in wholesale and retail markets," the Republican lawmakers wrote.
Congressmen Frist and Hastert called for federal agencies to search for possible market manipulation in refining, transportation, storage, marketing and distribution of petrol.
The high price of fuel has become a hot political issue before mid-term legislative elections in November with opposition Democrats accusing Mr Bush's Republican Party of playing ball with oil companies.
Representative Nancy Pelosi, leader of the Democratic minority in the House of Representatives, ridiculed the initiative from her Republican rivals.
"With record gas prices, record CEO pay packages, and record oil company profits, Speaker Hastert and the Republican Congress continue to give the American people empty rhetoric rather than join Democrats who are working to lower gas prices now," she said.
Soaring global oil prices have pushed the average price of petrol in the United States to nearly $US3 (A$4) a gallon (3.8 litres), with an increase of 33 US cents over the past month.