Next Tuesday, the day after Americans celebrate Labor Day, the U.S. Senate will begin floor debate on President Bush's plan for a new Homeland Security agency. It would pluck more than 170,000 workers from parts of 22 existing agencies like the U.S. Coast Guard and the Federal Emergency Management Agency. Federal unions representing 50,000 workers who would be among those being transferred are in full battle mode against parts of the administration's homeland security plan.

The central issue is what the Bush Administration calls "flexibility." Federal unions call it union-busting. The bill creating the homeland security agency sailed through the Republican-controlled House of Representatives by a vote of 295 - 132. It would give the new agency's director the freedom to redeploy as much as five percent of the projected $40 billion annual budget without a congressional okay in a national emergency.

That's one kind of flexibility.

But the provision that has angered federal unions is the homeland security director's authority to redefine workers' job descriptions and curtail, or even eliminate, protections they may have won through collective bargaining. Michael Franc, an analyst at the conservative Heritage Foundation think tank, argues that managers in a security agency need to be free of union restrictions that would hamstring the ability to respond to a crisis.

"Whether that's, say, shifting somebody from the Port of Newport News to Baltimore to reflect some intelligence information that there's an emerging threat...or if it means you have to redeploy some Border Patrol personnel, that sort of thing. It makes it very difficult for the managers of the agency to respond to an emerging threat without having first to appeal to a union shop steward and get permission under the collective-bargaining agreement," he said. "Some of those agreements, for example, dictate that if you move somebody from one station to another, there has to be a certain quality of hotels available, food services available, beds of a certain length, that sort of thing. That gets in the way of the agency's being able to respond, to head off at the pass, the next terrorist threat."

Without the kind of management prerogatives that exist in federal agencies like the FBI and the Federal Aviation Administration, Mr. Franc contends, the FAA would never have been able to quickly spring into action, grounding thousands of aircraft over the United States after the terrorist attacks on the morning of September 11 last year.

"You would hate to find out after the fact that we were not able to properly pre-empt a terrorist act because of various kinds of bureaucratic intrusions," he said. "You want to have the law enforcement and the security apparatus of this country be as nimble as possible in responding to these kinds of threats. Just hypothesize for a moment. If there is, God forbid, another major terrorist attack within our borders, this whole debate will be moot the moment we fail the American people."

Other supporters of the president's plan say the homeland security director should be able to assign people based on their skills, not their seniority or other hard-and-fast rules written into a union contract.

Although the details are still murky, it does not appear that unionized federal workers who would move into the new agency would be forced out of their unions. But labor leaders like Colleen Kelley say their bargaining rights and job security would be weakened. Ms. Kelley is president of the National Treasury Employees Union, which includes 12,000 U.S. Customs Service members likely to be transferred to the new security agency.

She and other federal union officials back a homeland security plan offered by Democratic senator Joseph Lieberman of Connecticut. It provides that the union workers transferred into the new security agency retain all rights that their unions had bargained.

Colleen Kelley angrily dismisses the notion that those who oppose the president's plan might somehow be unpatriotic at a time of war on terrorism.

"These employees have done the work that they do for decades, protecting the front lines of our country and the borders, doing exactly the same work that they're going to do under a new department," she said. "There is no one who supports this country having a national security system in place that is effective more than these employees. They are dedicated. They are committed. They are trained. And they want to do this work. So there is absolutely no question of the loyalty, the commitment, and the patriotism of these employees or of our members. This is about providing the security that this country needs, not at the risk of stripping away rights of federal employees. It does not have to be an either-or debate."

President Bush may call it "flexibility," treasury union president Kelley maintains, but she calls it just a fancy word for breaking the union. "I think there is an interest on the part of the administration to write their own rules, to start with a blank piece of paper and just to design what it is they want to design without having to deal with anyone else," she said. "And I think that includes front-line employees and the unions that represent them."

Senior U.S. senators, including Democrat Robert Byrd of West Virginia, say they will insist on prolonged debate about the merits of the homeland security bill. Thus President Bush's plan to sign the bill on the anniversary of the September 11 attacks seems unrealistic. The president has promised his first veto if the final measure does not give his homeland security managers the kind of personnel control contained in the House bill. And everyone on both sides of the issue is choosing words carefully in this election year.