Updated

Advocates of rewriting the USA Patriot Act (search) are claiming momentum after the House, despite a White House veto threat, voted to restrict investigators from using the anti-terrorism law to peek at library records and bookstore sales slips.

Wednesday's 238-187 vote came as lawmakers ramped up efforts to extend the Patriot Act, which was passed quickly in the emotional aftermath of the Sept. 11, 2001, terrorist attacks. When Congress passed the law, it included a sunset provision under which 15 of the its provisions are to expire at the end of this year.

White House press secretary Scott McClellan said Thursday that weakening of the act could draw a veto from President Bush, who pressured Congress to renew all provisions of the law during a visit with Ohio police in Columbus last week.

"There's still a long way to go in the legislative process and as he indicated last week, the president is going to continue urging Congress to renew and make permanent all provisions of the Patriot Act," McClellan said. "They are all vital tools in our efforts to protect the American people and disrupt plots from happening."

Since the Patriot Act passed, liberals and libertarian-oriented conservatives have pressed for changes, citing privacy and civil liberties concerns.

"No question, this is a real shot in the arm for those of us who want to make changes to the USA Patriot Act," said Rep. Bernard Sanders (search), I-Vt., sponsor of the provision that would curtail the government's ability to investigate the reading habits of terror suspects. He said the vote would help "rein in an administration intent on chipping away at the very civil liberties that define us as a nation."

The vote reversed a narrow loss last year by lawmakers concerned about the potential invasion of privacy of innocent library users. They narrowed the proposal this year to permit the government to continue to seek out records of Internet use at libraries.

The House is debating a $57.5 billion bill covering the departments of Commerce, Justice and State. The Senate has yet to act on the measure, and GOP leaders often drop provisions offensive to Bush during final negotiations.

The Justice Department said in a letter to lawmakers that as of March 30, federal investigators had not used the Patriot Act to obtain library or bookstore records but that the authority provides "an important tool for investigating and intercepting terrorism."

"It bodes well that the first vote Congress has taken on the Patriot Act this year has been in favor of liberty and freedom," said Gregory Nojeim, a lobbyist for the American Civil Liberties Union.

Supporters of rolling back the library and bookstore provision said that the law gives the FBI too much leeway to go on fishing expeditions based on what people read. Innocent people could get tagged as potential terrorists based on what they check out from a library, critics said.

"If the government suspects someone is looking up how to make atom bombs, go to a court and get a search warrant," said Rep. Jerrold Nadler, D-N.Y.

Supporters of the Patriot Act countered that the rules are potentially useful and argued that the House was voting to make libraries safe havens for terrorists.

"If there are terrorists in libraries studying how to fly planes, how to put together biological weapons, how to put together chemical weapons, nuclear weapons, ... we have to have an avenue through the federal court system so that we can stop the attack before it occurs," said Rep. Tom Feeney, R-Fla.

Last year, a similar provision was derailed by a 210-210 tie after several Republicans were pressured to switch votes.

In the meantime, a number of libraries have begun disposing of patrons' records quickly so they won't be available if sought under the law.

Attorney General Alberto Gonzales (search) told Congress in April that the government has never used the provision to obtain library, bookstore, medical or gun sale records.

But when asked whether the administration would agree to exclude library and medical records from the law, Gonzales demurred. "It should not be held against us that we have exercised restraint," he said.

Authorities have gained access to records through voluntary cooperation from librarians, Gonzales and FBI Director Robert Mueller said.