Groups challenging the government's broader use of surveillance powers for post-Sept. 11 law enforcement lost a major battle Monday when the U.S. Supreme Court refused to hear their appeal.

The American Civil Liberties Union and other organizations wanted the high court to consider whether the government's new federal telephone eavesdropping and e-mail surveillance powers were going too far in the wake of the 2001 terrorist attacks.

The groups were attempting an unusual move: to bring the suit on behalf of unnamed plaintiffs, people who did not know if they were being monitored by federal law enforcement. The court would have to give special permission for such a move, which it soundly rejected without comment in its ruling Monday.

The decision did not judge the merits of the case against the government. The issue is expected to return to the court in the future.

At the center of the debate is the Foreign Intelligence Surveillance Act Court, which meets behind closed doors to approve wiretaps and secret property searches of people suspected of espionage or terrorism. Under the U.S.A. Patriot Act, which was passed after the terrorist attacks, the criteria for the so-called spy court's powers were expanded to include secret searches and wiretaps of criminals not necessarily connected to terrorism or espionage.

That has sparked concern among civil liberties advocates and some members of Congress who say the Justice Department is making a grab for more power without regard to American citizens' rights.

Last year, a review panel of the FISA court ruled that the administration did not misinterpret the Patriot Act in extending its surveillance powers to suspects not necessarily connected to terrorism.

Meanwhile, Attorney General John Ashcroft has announced that 170 emergency warrants have been approved by FISA since the 2001 attacks, more than triple the number of total warrants received by the court in the last 23 years.

In addition, more than 1,000 total warrant applications were requested to FISA in 2002, including the emergency warrants, according to Ashcroft.

While acknowledging that the use of such surveillance is important in the war on terror, some members of Congress said the court should disclose as much information as possible about the suspects and their cases. Under FISA, suspects do not know they are being monitored and they do not have access to the evidence against them once they are prosecuted. Furthermore, there is no public access to the proceedings.

Sens. Patrick Leahy, D-Vt., and Charles Grassley, R-Iowa, are sponsoring legislation that would require the Justice Department to publicly account for the use of FISA warrants.

The ACLU had filed challenges in Michigan and New Jersey, on behalf of media organizations seeking access to hearings involving foreigners swept up in the terrorism probes, and hopes to push the issue of disclosure on a number of levels.

"Disclosure of basic information about FISA surveillance is not going to hamper our anti-terrorism efforts, nor will it hamstring Justice's law enforcement efforts," said Timothy Edgar, legislative counsel for the American Civil Liberties Union. "What it will do ... is go a long way toward assuaging growing public mistrust of the government."

So far, the 3rd U.S. Circuit Court of Appeals in Philadelphia ruled that the attorney general has the right to close the hearings for reasons of national security. The ACLU appealed the decision. The government has until next month to appeal an Appeals Court decision that went the other way.

"The courts continue to have a critical role in ensuring that the government's efforts to protect national security are done in a manner that is consistent with protecting civil liberties," said Steven Shapiro, the ACLU's legal director.

The Associated Press contributed to this report.