Highlighting their campaign against a chief Defense Department contractor, Democratic lawmakers say two former Halliburton employees have evidence the company routinely wasted U.S. taxpayers' money.

While one ex-employee asked that his name not be disclosed, a second, Henry Bunting, agreed to testify Friday before the Senate Democratic Policy Committee (search) - an organization of Democratic senators.

Two of the most persistent Halliburton (search) critics wrote Pentagon auditors on Thursday specifying the allegations of wasteful practices. Reps. Henry Waxman, D-Calif., and John Dingell, D-Mich., said 90 percent of the company's global support contract - worth $3.7 billion so far - is for work in Iraq.

Halliburton, run by Vice President Dick Cheney before his 2000 vice presidential campaign, has consistently denied overcharges.

Bunting was a field buyer who filled requisitions from Halliburton employees by locating vendors. The second ex-employee was a procurement supervisor who did similar work.

According to Waxman and Dingell, Bunting and the unidentified whistleblower contend:

--Top Halliburton officials frequently told employees that high prices charged by vendors were not a problem because the U.S. government would reimburse the costs and then pay the company an additional fee.

-Higher than necessary prices were paid for ordinary vehicles, leased for $7,500 a month, and for furniture and cellular telephone service.

-Halliburton tried to keep as many purchase orders as possible below $2,500 so its buyers could avoid the requirement to solicit quotes from more than one vendor.

-Supervisers provided buyers with a list of preferred Kuwaiti vendors, including companies that charged excessive prices. Buyers were not encouraged to identify alternative vendors.

Congressional Democrats and the party's presidential candidates have made Halliburton's extensive government contracts a major election issue, contending the business showed favoritism toward Cheney's former company.

The vice president has repeatedly said he had no involvement with the company once he left Halliburton before the 2000 campaign.

The letter was sent to the Defense Contract Audit Agency (search), which found in a preliminary audit that Halliburton may have overcharged taxpayers $61 million in delivery of oil to Iraq.