President Bush signed legislation Tuesday establishing new rules for interrogating and trying suspected terrorists, but the fight over how...

WASHINGTON — President Bush signed legislation Tuesday establishing new rules for interrogating and trying suspected terrorists, but the fight over how to deal with detainees is far from over.

The new law is under attack in court, and no one is likely to be brought to trial under the new rules anytime soon. Even some lawmakers who voted for the legislation questioned its constitutionality.

Although the law’s future is uncertain, critics and supporters agreed that its enactment marks a major shift in the nation’s approach to terrorism and some legal principles. Programs that Bush launched in secret now have the support of Congress.

The Military Commissions Act of 2006 clears the way for the CIA to resume aggressive interrogations in secret prisons and denies suspected terrorists the right to challenge their detentions in civilian courts. It also permits the use of evidence obtained through coercion and lets the president draw the line between acceptable interrogation techniques and impermissible torture.

While Bush hailed the legislation as a potent weapon against terrorists, critics called it a stain on America’s reputation as a champion of human rights and civil liberties.

“It is a rare occasion when a president can sign a bill he knows will save American lives,” Bush said at a White House signing ceremony.

The ceremony was part political rally for a GOP struggling to retain control of Congress three weeks before midterm elections. Republican leaders said the legislation showed they were a party of strength and assailed Democrats for not backing the bill.

“The Democratic plan would gingerly pamper the terrorists who plan to destroy innocent Americans’ lives,” said House Speaker Dennis Hastert, R-Ill.

Sen. Russ Feingold, D-Wis., said: “The fundamental fairness of the American people and legal system are among our greatest strengths in the fight against terrorism. We will look back on this day as a stain on our nation’s history.”

The Center for Constitutional Rights, which has filed two challenges to the law on behalf of detainees, said it would fight the changes “at every turn, using every tool at our disposal, until we reverse this affront to the rule of law.”

Legal experts said the anticipated court battles make it unlikely that any of the roughly 435 detainees at the U.S. naval base at Guantánamo Bay, Cuba, would face trial before a military commission soon.

Legal scholars on both sides of the issue agreed the law is most vulnerable to challenge on the issue of denying detainees access to civilian courts unless they’re U.S. citizens.

The ability of suspects to challenge their imprisonment, known as the right of habeas corpus, dates to the Magna Carta in 1215 and is considered a bedrock legal principle.

Material from the Los Angeles Times is included in this report