The Homeland Security Department announced Tuesday that some criminal investigators from the former Immigration and Naturalization Service will be promoted next month and will no longer be eligible for union representation.

The move was announced in an e-mail from Michael Garcia, assistant secretary of Homeland Security for Immigration and Customs Enforcement (ICE). Eligible investigators will be promoted on May 2 from a GS-12 to a GS-13 in the General Schedule pay system.

DHS officials are making their pay system fair by bringing legacy INS investigators up to the same level as criminal investigators from the former Customs Service, according to Russ Knocke, an ICE spokesman.

"Issues relating to criminal investigator pay parity have been resolved," Knocke said. "What it's really doing is creating equal pay for equal work."

To be eligible for the promotion, the legacy INS investigators must have one year of experience as a GS-12, a satisfactory job evaluation and approval from a supervisor. The promotion will include a pay raise - ranging from 6 to 15 percent. No additional training will be required, Knocke said.

The investigators, however, will no longer be members of the American Federation of Government Employees or participate in collective bargaining. Under the law that established the Homeland Security Department, officials are allowed to remove investigators from union representation because their jobs include national security and counterterrorism work. Of the 1,473 investigators who are eligible for the promotion, 498 are active union members.

DHS will stop the automatic withdrawal of their union dues on April 18.

The union has been battling with DHS over a wholesale overhaul of the personnel system that will eliminate the General Schedule pay system, implement "pay banding" by occupation, and streamline the appeals process. Union officials cried foul over the latest move to bar ICE investigators from collective bargaining.

"AFGE intends to fight this attempt to take away union rights at all possible levels," said union president John Gage.

"Union contracts and the rights of federal employees cannot be eliminated simply by re-drafting a position description and writing in the word 'terrorism.' The new Homeland Security law requires that the primary job duty must be directly related to terrorism investigation. The mere fact that it may be one of many duties and that there is a possible connection to the duty is insufficient."

Gage said also that DHS made the decision without first discussing it with union officials.

"We had hoped for a serious collaboration with DHS, and we had been assured that it would take place," he said.

"This recent action appears to be a broken promise."

Knocke said the counterterrorism mission at ICE justifies the decision, and he rejected Gage's accusation that there had been no collaboration.

"The implication that we haven't coordinated with union leadership is not entirely accurate," he said. "We've had meetings and notifications, and we have absolutely been coordinated."

Inside ICE, some legacy INS agents expected to lose collective bargaining rights. "The writing appeared to be on the wall with that issue," said one agent. "The real question is whether or not pay banding and the changes to the new HR system will erase even more employee rights."

Jason Peckenpaugh contributed to this report