The Senate voted 68-30 to attach the amendment sponsored by Democratic Sen. Al Franken of Minnesota to a larger defense spending bill. A vote on the full bill was expected later.
Franken said he sponsored the measure in response to the case of former KBR/Halliburton employee Jamie Leigh Jones, who alleges she was raped by co-workers while in Iraq in 2005. She went public with her story in 2007.
"Contractors are using fine print to deny women like Jamie Leigh Jones their day in court," Franken said during debate on the amendment.
Jones is suing Halliburton Co. and its former subsidiary KBR. The company has said her employment agreement requires her to resolve the claim through arbitration. An appeals court ruled recently her lawsuit can go to court.
KBR Inc. and Halliburton, which split in 2007, have disputed Jones' account of how the companies responded to her allegations. KBR spokeswoman Heather Browne said previous comments of the company stand and declined further comment. A Halliburton representative could not be immediately reached when the company was contacted after business hours.
Sen. Jeff Sessions, R-Ala., opposed the amendment saying the Defense Department did not want it. He said it would invalidate due process rights of employers and employees and arbitration can be better and less expensive for employees.
"The Congress should not be involved in writing or rewriting contracts," Sessions said.
Specifically, the amendment prohibits DOD from spending federal money on existing or new contracts if the contractor or a subcontrator requires the employee or an independent contractor to resolve sexual assault, discrimination or certain other claims through arbitration.
The House has not voted on a defense spending bill. Differences between approved House and Senate bills will be ironed out in a conference committee. Franken said the Senate vote should help ensure his amendment is in the final compromise defense spending bill.
The Associated Press usually does not identify people alleging sexual assault, but Jones' face and name have been broadcast in media reports and on her own Web site.
Jones, of Houston, was at the Senate when the amendment was approved. After the vote, she met Franken in a room near the Senate floor, hugged him and thanked him. "Way to go," Franken told her. He called her courageous and persistent.
Jones said the amendment's passage "means the world to me."
"It means that every tear shed to go public and repeat my story over and over again to make a difference for other women was worth it," she said. Jones testified about the alleged assault before Congress and other women employed by contractors have made similar allegations.
Jones has said she was raped in her company barracks by several co-workers in July 2005 after she was drugged. She has said she was placed under armed guard and held in a shipping container for hours after reporting the alleged attack.