The Senate voted Tuesday to give 45,000 airport screeners the same union rights as border patrol, customs and immigration agents, despite a veto threat from the White House.

The 51-46 vote was on an amendment by Sen. Jim DeMint, R-S.C., to remove the union rights from a broad anti-terrorism bill to implement recommendations of the 9/11 commission previously rejected by Congress.

The House passed a similar anti-terrorism bill with the same union provision for airport screeners in an indication of organized labor's strength with Democrats now running Congress.

Republicans vowed to strike the union provision when negotiators sit down to merge the House and Senate bills together to implement recommendations of the 9/11 commission previously rejected by Congress.

"We're not going to let big labor compromise national security," said Sen. Mitch McConnell, R-Ky., noting there are not enough votes in either the House or Senate to override a veto by President Bush.

Screeners "deserve our respect, not our indifference," said Sen. Sherrod Brown, D-Ohio. Brown said collective bargaining rights wouldn't allow screeners to strike, and would grant them basic protections from overwork, dangerous conditions and retaliation if they report security breaches.

"It's absolutely absurd," said Sen. Richard Burr, R-N.C. "Terrorists don't go on strike. Terrorists don't call their union to negotiate before they attack."

White House officials released a statement last week saying President Bush's senior advisers would recommend that he veto the bill if it includes the union provision for screeners.

When Congress created the Homeland Security Department after the Sept. 11, 2001 terror attacks, it specifically ruled out collective bargaining rights for screeners, who were becoming federal employees under the new Transportation Security Administration.

There are about 53,000 Homeland Security employees who have collective bargaining rights, according to the American Federation of Government Employees.

The screeners' boss, TSA chief Kip Hawley, told a Senate panel Monday that giving airport screeners collective bargaining rights would hinder the agency's flexibility to move them around in response to terrorist threats.

"Going backwards to a system that adds bargaining, barriers and bureaucracy to an agency on whom travelers depend for their security can be characterized as many things, but it does not improve security," Hawley told a subcommittee of the Homeland Security committee.

John Gage, president of the American Federation of Government Employees, said unions represent many other federal workers who protect the public from terrorism.

"When we hear that collective bargaining rights will affect our national security, I really take offense," said Gage, whose union represents airport screeners but not for collective bargaining purposes.

A stumbling block to Senate passage was removed Thursday when the Homeland Security Department agreed to grant states an extra year and a half to comply with new driver's license standards passed in the 2005 REAL-ID Act.

The nation's governors and Congress said there wasn't enough money for states to convert their databases or enough time to develop driver's licenses that critics complain amount to a national ID card and could promote identity theft.

The Senate bill would upgrade security on passenger and freight railroads and require all cargo carried on commercial passenger aircraft to be screened for bombs.

It would provide funds for state and local emergency communications systems, expand a visa waiver benefit for favored countries and improve intelligence sharing among federal, state and local officials.