Washington ? A senior Justice Department official said Friday that a ruling by a secretive federal court that scales back the department’s efforts to share intelligence information with FBI agents has hurt the ability of law enforcement to protect U.S. citizens from ongoing terrorist plots.

The confidential May ruling by the Foreign Intelligence Surveillance Act court made public Thursday has had an unseen but significant impact on the nation’s war on terrorism, the official said during a Justice Department briefing on the status of the investigation into the Sept. 11 attacks and other terrorism-related matters. Also Friday, the Justice Department released its appeal of the ruling, which it filed late Thursday.

Several Democratic lawmakers praised the FISA court, as it is known, saying its ruling was instrumental in protecting the civil rights of Americans from undue spying by a Justice Department that has become overly aggressive in its self-declared war on terrorism.

Justice Department officials vehemently disagreed and warned that unless the court ruling is overturned, they will be hamstrung in their efforts to enact important counterterrorism measures included in the USA Patriot Act passed last year by Congress.

Of particular concern, according to the senior official and others in the Justice Department, is the FISA court’s order that federal prosecutors, FBI agents and intelligence operatives keep intact a wall between those investigating ongoing criminal activity and those gathering intelligence on potential terrorist attacks and acts of espionage.

In effect, the court’s ruling means “that in order to bring a (criminal) case against someone, we have to shut down intelligence channels and we’re going to be blind” as to what suspected terrorists are doing, said the official, who spoke on condition of anonymity. “Or it’s the reverse, that in order to keep seeing what’s going on, we’ll have to kind of sit with our hands tied and let people run around and do bad things. So I do think it has impeded our ability to get closer coordination.

“I think we are better than we were prior to Sept. 11” in terms of ferreting out terrorist plots and stopping them, the official added. “But we are not where we could be and where the American people have a right to expect we will be if the law is fully deployed in the way that we want.”

The looming legal battle over the FISA ruling underscores the debate about how far the FBI and the Justice Department should be able to go in gathering intelligence in the fight against terrorism.

The Foreign Intelligence Surveillance Act of 1978 was passed in response to the Nixon administration’s abuse of its intelligence-gathering powers to spy on its political enemies. It was intended to distinguish between the government’s efforts to battle crime at home and its need to gather intelligence on suspected foreign agents. Warrants to allow such searches required approval of the FISA court.

In the mid-1990s, then-Atty. Gen. Janet Reno erected a firewall between intelligence-gathering investigations and criminal probes to prevent agents from overstepping their authority because the warrants are so secretive and the methods of investigation so invasive.

Often, FISA-approved searches are conducted without having to notify the suspect, unlike warrants in routine criminal probes. Reno ordered that, to win approval for such warrants, intelligence agents must meet higher legal standards to justify such covert searches.

After the Sept. 11 attacks, Atty. Gen. John Ashcroft succeeded in convincing Congress to loosen the rules for using FISA-approved secret wiretaps and searches as part of the USA Patriot Act.

In particular, Ashcroft sought to diminish the barrier between criminal probes and intelligence-gathering efforts by the FBI particularly when it comes to information developed from the use of secret wiretaps and search warrants. Ashcroft said the effort to expand the cooperative efforts among FBI agents, intelligence operatives and prosecutors was a keystone in the effort to protect the nation from terrorist attacks. But on May 17, the highly secretive FISA court said it had grown so concerned about Ashcroft’s behind-the-scenes efforts to broaden the Justice Department’s spying abilities that it ordered Ashcroft to scale back his efforts significantly.

The court rejected a secret request by the Justice Department to allow increased cooperation and information-sharing among the two camps, saying it was “not reasonably designed” to safeguard the privacy of Americans.

The court specifically warned against efforts by prosecutors to give more legal advice to agents in the field about how they could use information gained under FISA-approved search warrants and wiretaps in criminal cases.

The court also disclosed that its panel of federal judges have voiced grave misgivings for years about the way the Justice Department has handled top-secret wiretaps and searches in terror cases. It reported, for instance, that under the Clinton administration, the FBI gave false information in more than 75 requests for top-secret warrants in cases related to international terrorism and espionage probes.

The Justice Department’s formal appeal of the FISA ruling was signed by Ashcroft himself. The 78-page legal brief says the ruling misinterprets the broader powers granted to the department under the Patriot Act.

The appeal marked the first time that the appellate panel has ever been used to contest a ruling by the FISA court, which has approved all but a handful of the thousands of requests for wiretaps and search warrants requested by the FBI and the Justice Department since it was established under a 1978 law.

Because of that ruling, and the FISA court’s concerns about abuses of the FISA laws, the Justice Department hasn’t implemented important aspects of the Patriot Act, the senior official said, and hasn’t engaged in the kind of information-sharing and cooperation that it wanted to under the Patriot Act.

The official said some information sharing is occurring between the criminal investigators and intelligence operatives but that “it takes longer, and it is harder and it’s more complicated and time is important. Time is of the essence.”

“I think we are better than we were before, but it is still very cumbersome,” the official said.

Rep. Jerold Nadler, D-N.Y., a member of the Judiciary Committee that oversees the Justice Department, said the FISA court’s ruling had helped protect Americans from undue intrusion into their privacy.

“Since his appointment as attorney general, and certainly since Sept. 11, Ashcroft has shown himself to be one of the attorney generals most contemptuous of law and civil liberties. It’s good to see the courts are starting to rein him in,” said Nadler. “We must wage a war against terror but we must not do so in a way that destroys civil liberties and civil rights of Americans.”

Added Rep. Maxine Waters, D-Calif.: “I think the court is absolutely correct in reining him in. We gave (Ashcroft) more powers, but he’s going beyond that.”

Rep. Barney Frank, D-Mass., ranking member on the Judiciary Committee, said he was not sure whether he would support the Justice Department’s appeal.

“I have to look very carefully. Some sharing is OK and some isn’t,” Frank said. “You shouldn’t use a terrorism hook to drop the standard for a garden variety crime. That’s abusive.”