A federal judge has blocked the Bush administration's plans to revise personnel and pay rules at the Department of Homeland Security, saying the government-wide change of labor rules fails to protect workers' right to bargain collectively.

The decision Friday by U.S. District Judge Rosemary M. Collyer is a victory for the National Treasury Employees Union and other labor groups. They argued that the proposal, which was set to be implemented Monday, would have taken away their bargaining rights on issues such as employee assignments and technology use.

Labor groups have filed similar challenges against a Pentagon plan to revise Defense Department labor rules.

This is an "enormous and critically important win for the rights of federal employees not only in DHS but in all federal agencies," said Colleen M. Kelley, president of the NTEU.

In the ruling, Collyer said the new rules exceed the scope of federal law, citing in particular provisions giving a department official unchecked authority to change negotiated positions in a collective-bargaining agreement.

"The regulations fail because any collective bargaining negotiations pursuant to its terms are illusory: the secretary retains numerous avenues by which s/he can unilaterally declare contract terms null and void, without prior notice to the unions or employees and without bargaining or recourse," Collyer wrote.

Jaclyn Lesch, a spokeswoman for the Justice Department, which defended the rules in court, declined to comment Saturday on the ruling. The government's lawyers have said that the new rules, which were devised after Congress passed the Homeland Security Act of 2002, are necessary to give officials more flexibility to respond quickly to terrorist threats.