The 43,000 Transportation Security Administration officers are already allowed to join a union but federal law prevents the union from bargaining on their behalf to contest workplace assignments, filing grievances or representing them in disciplinary matters, The New York Times reported Wednesday.
"There's no good reason to deny these rights to these people," said U.S. Sen. Joseph Lieberman, I-Conn.
Mark Roth of the American Federation of Government Employees said representation would add to screeners' morale.
"How safe is the public if officers who see security breaches that result from mismanagement cannot disclose that because they fear they could be fired?" Roth said.
The move is opposed by the Bush administration as well as Senate Republicans. Tuesday, in a letter to the White House, U.S. Sen. Jim DeMint, R-S.C., said he and 35 other Senate Republicans were prepared to sustain a veto, the Times reported.
Kip Hawley, the security agency's administrator, said hiring staff members to handle union relations would cost $160 million, the report said.