A bill due to be put forward by the panel's Republican chairman, Sen. Pat Roberts of Kansas, would allow the FBI to subpoena materials ranging from health and library records to tax documents without a judge's initial approval, as part of federal terrorism and intelligence probes, committee aides said.

The aides, who spoke on condition of anonymity, said the change would provide counterterrorism officials with the same subpoena powers wielded by criminal investigators.

"The discussion that led to drafting the provision was, if it's a tool that's available in hundreds of criminal contacts then why not provide that same tool to national security investigators as well," said one committee aide.

"There really wasn't a whole lot of cogent argument in opposition to it."

But civil liberties advocates warned that the proposal would mean a dramatic expansion of government powers eclipsing the subpoena authorities provided in the Patriot Act.

"It's a power grab. This increases the executive branch's power to secretly search and seize people's medical records, tax records, firearms purchase records and information about the books and magazines they read," said Lisa Graves, senior legislative counsel at the American Civil Liberties Union.

"It's a bad idea. It's a wrong step in the wrong direction," she said.

Under the Patriot Act, the FBI can issue documents known as national security letters to seize business records, and a wider range of documents can be subpoenaed with approval of a special federal judge.

BROADER POWERS

But aides predicted the broader powers provided by administrative subpoenas would render the narrower Patriot Act provisions obsolete within a year. The new bill would allow FBI officials from Director Robert Mueller to special agents in charge of FBI field offices to issue the subpoenas that would apply to "335 different criminal statutes," an aide said.

In cases determined to involve a threat to national security, the FBI could also prevent subpoena recipients from telling the target of the investigation that his or her records have been sought or confiscated.

President Bush, whose administration has lobbied hard for Patriot Act renewal, has called on Congress to authorize the FBI to issue administrative subpoenas in terrorism investigations.

At an April 27 hearing before the Senate Select Committee on Intelligence, Attorney General Alberto Gonzales and Mueller both gave the idea vocal support.

The bill, which has not been publicly released, would add an administrative subpoena provision to the Foreign Intelligence Surveillance Act, or FISA, while calling for permanent reauthorization of eight intelligence-related sections of the USA Patriot Act that are due to expire at year's end.

Under FISA, which deals with intelligence and terrorist activities involving foreign powers, administrative subpoenas could not be used against the domestic activities of U.S. citizens, said the aides. Recipients also could challenge the subpoenas, forcing the FBI to seek enforcement through federal district court.

The Senate Select Committee on Intelligence is expected to discuss the proposed legislation at a public hearing sometime next week and then hold a closed-door markup session a few days later that could send it to the Senate floor for a vote.

The panel initially planned to hold its markup session on Thursday but postponed the meeting.