WASHINGTON – Four years after the USA Patriot Act became law, the fiery debate surrounding it will be rekindled today as congressional lawmakers consider whether to renew provisions of the law that are set to expire at the end of this year.

The Bush administration has said it is crucial to the war on terrorism that the police and surveillance powers that were temporarily expanded in the aftermath of the September 11, 2001, terrorist attacks be permanently expanded, but an unlikely coalition of liberals and conservatives is calling for an overhaul of the law.

The criticism comes as the attorney general, Alberto Gonzales, and the director of the FBI, Robert Mueller, today testify before the Senate Judiciary Committee about how the Justice Department has used the USA Patriot Act and why all its provisions should be made permanent.

They appear before the House Judiciary Committee tomorrow.

Mr. Gonzales calls the law a “vital part of our defense of protecting lives and liberties,” and “has addressed critical vulnerabilities in America’s pre-September 11th defenses.”

A newly formed national network of conservative groups, called Patriots to Restore Checks and Balances, and the American Civil Liberties Union are calling on lawmakers to grill the officials on the use of the law. They have embarked on what they say will be a long-term lobbying effort aimed at attempting to scale back the expanded search and seizure powers at a time when the Bush administration is trying to make them permanent.

The dozen conservative groups include the American Conservative Union, Americans for Tax Reform, and the Citizens’ Committee for the Right to Keep and Bear Arms.

The Bush administration’s plan to make the provisions permanent is “not a foregone conclusion,” the executive director of the American Policy Center, Peyton Knight, said. The American Policy Center is one of the coalition members.

“This has snowballed since the Patriot Act’s inception – first it was the anti-Bush people, but now conservatives are starting to wake up, too,” he said.

Some conservative groups that frequently support the Bush administration are taking aim at several provisions the president wants to make or keep permanent.

In particular, they are concerned about a provision that allows the collection of personal information even without strong evidence linking the targets to terrorism. They are also concerned that the law defines terrorism so broadly that it could include acts of protected speech and civil disobedience.

They are also worried about an already permanent provision known as “sneak and peek,” which allows government agents to secretly search people’s homes and businesses, and to seize their property, in federal criminal investigations not limited to terrorism cases. Although the searches require the approval of a judge, the target of the search is informed of the search only sometime after the fact.

“When you give government powers, there is the real danger the power will be abused,” the president of Americans for Tax Reform, Grover Norquist, said.

If the contested powers can be demonstrated to be necessary, they could be reauthorized every four years in perpetuity, Mr. Norquist said.

Today’s hearing comes a week after a Senate panel scolded the Department of Justice for not answering requests by lawmakers about the effects of 16 provisions that are scheduled to “sunset” in December.

More information is needed to evaluate the provisions that have roused consternation and unease around the nation, according to Senator Kyl, a Republican of Arizona, and Senator Feinstein, a Democrat of California who is chairwoman of the Senate Judiciary Subcommittee on Terrorism, Technology, and Homeland Security.

The debate comes as Montana recently became the fifth state to pass a resolution against the Patriot Act. The resolution prohibits state agencies from participating in what it called “abusive security measures.” Hundreds of local governments have passed similar resolutions, according to the American Civil Liberties Union.

Supporters of the law note that Ms. Feinstein, a frequent critic of the administration’s policies, has said that she has looked for and not found evidence of abuses under the law. But critics are not satisfied.

“The barometer for whether the law is good or bad should not be how long it takes for a victim to come forward,” Mr. Peyton said. “We believe these provisions violate the constitution. If they are used once in the manner in which they have been written, it’s an abuse,” he said.

That lack of evidence of abuse will be a strong argument in favor of making permanent the provisions, a senior fellow in homeland security at the Heritage Foundation, James Carafano, said.

The temporary provisions are likely to be renewed, he predicted, especially if they face an up-or-down vote and are not combined with an effort to expand police powers in new ways.

“When you get into hearings, you’ll see there are few examples of people being abused. If they go to a closed door session, they’ll see a great deal of evidence that the law is useful,” he said.

The Patriot Act was enacted in 2001 with the support of Republicans and Democrats in both chambers. The vote in the Senate was 98 to 1; in the House it was 357-66.

Mr. Carafano predicted that most lawmakers will be reluctant to vote against the provisions they helped enact.

Critics of the act argue otherwise.

“These are the same people who didn’t read the bill when they voted on it,” Mr. Knight said. “Once lawmakers read these provisions and understand the potential for abuse, then they will absolutely side with us,” he said.

The ACLU yesterday alleged that the Patriot Act has been “abused and misused repeatedly by the government since its enactment,” and called on lawmakers to press Messrs. Gonzales and Mueller to act on the allegations.

The ACLU contends that the Patriot Act was used to search the home of a Muslim attorney, Brandon Mayfield, whom the government accused and detained as a perpetrator of the recent train bomb in Madrid. The Justice Department has said Mr. Mayfield was detained under the authority of a preexisting law.

The Justice Department said yesterday that “sneak and peek” procedures were used 108 times between April 2003 and January 2005, accounting for less than 0.2% of the search warrants used by law enforcement between April 2003 and January 2005 – all cases were approved by a judge.