WASHINGTON  An effort by the New York Police Department to get broader latitude to eavesdrop on terrorism suspects has run into sharp resistance from the Justice Department in a bitter struggle that has left the police commissioner and the attorney general accusing each other of putting the public at risk.

The Police Department, with the largest municipal counterterrorism operation in the country, wants the Justice Department and the Federal Bureau of Investigation to loosen their approach to the federal law that governs electronic surveillance. But federal officials have refused to relax the standards, and have said requests submitted by the department could actually jeopardize surveillance efforts by casting doubt on their legality.

Under the law, the government must in most cases obtain a warrant from the special Foreign Intelligence Surveillance Court before it can begin electronic monitoring of people suspected of spying or terrorism. The requests are subjected to sharp scrutiny, first by lawyers at the F.B.I., then by lawyers at the Justice Department, and finally by the court itself.

New York’s department, as a local police force, cannot apply directly, but must seek warrants through the F.B.I. and the Justice Department. The police want those agencies to expedite their requests, and say that the federal agencies unfairly blocked the city’s applications for surveillance warrants, first in June and then in September. The disagreement, in which the Bush Justice Department has taken a more cautious approach than police officials, is something of an unexpected twist for an administration that has more often seemed willing to stretch legal boundaries to fight terrorism.