WASHINGTON — Attorney General-designate Michael Mukasey said Wednesday the president doesn't have the authority to use torture techniques against terrorism suspects, a stance not taken by predecessor Alberto Gonzales and considered key to the nominee's confirmation.

Mukasey repudiated a 2002 memo by then-Assistant Attorney General Jay Bybee that said the president has the power to issue orders that violate the Geneva Conventions as well as international and U.S. laws prohibiting torture. The memo was later disavowed and overridden by an executive order governing interrogation and treatment of terrorism suspects, which allowed harsh questioning of suspects but included a vaguely worded ban on cruel and inhuman treatment.

"The Bybee memo, to paraphrase a French diplomat, was worse than a sin, it was a mistake. It was unnecessary," Mukasey told the Senate Judiciary Committee under questioning by Chairman Patrick Leahy, D-Vt.

Leahy said that he and other senators did not vote for Gonzales in large part because he refused to disavow the Bybee memo.

Mukasey's confirmation was all but assured even before he made the statement at the top of proceedings on whether to confirm him as the nation's 81st attorney general. Democrats from Majority Leader Harry Reid and Leahy on down long have predicted easy and quick Senate approval.

Within minutes of convening the hearings, Leahy elicited specific assurances from the nominee that had been sought by liberal interest groups and senators who had endured months of Gonzales' faulty memory during congressional hearings and highly parsed statements.

Under questioning by Leahy, Mukasey promised to bar all but the top Justice employees from taking calls or making calls "to political figures to talk about cases," a problem under Gonzales.

"Partisan politics plays no part in either the bringing of charges or the timing of charges," Mukasey said.

Mukasey, a legal adviser to Republican presidential candidate Rudy Giuliani, pledged to recuse himself from matters involving his longtime friend and legal colleague.

And under questioning from the panel's senior Republican, Sen. Arlen Specter of Pennsylvania, Mukasey said he'd have no problem resigning if the president ignores his legal or ethical reservations about administration policy.

"I would try to talk him out of it or leave," Mukasey replied.

Measuring Mukasey's independence from the White House has long been an ephemeral, but key, factor in securing support from lawmakers of both parties. Gonzales was accused of being a Bush ally unwilling or unable to stop underlings from broaching ethical and legal boundaries.

The legal controversies that plagued the department under Gonzales spanned the public policy spectrum. From the administration's torture techniques to the president's controversial eavesdropping program and whether nine federal prosecutors were purged for political reasons, the scandals and congressional investigations left the Justice Department leaderless and demoralized.

Setting the more than 100,000-member law enforcement agency back on its feet would be the first order of business. Since the start of the year and Congress' probe of the prosecutor firings, at least 15 senior Justice Department officials have resigned — including Gonzales, his second- and third-in-command and five assistant attorneys general.

"This is a job interview for a big job, a big job that has become even bigger," Leahy said as he opened the proceedings. "The next attorney general has to begin to regain the public trust."

Sen. Charles Schumer, a Democrat from Mukasey's home state of New York, said he already had heard the answer he wanted in a private meeting with Mukasey a day earlier. Schumer said he asked the nominee, "Will you have the courage to look squarely into the eyes of the president of the United States and tell him 'no,' if that is your best legal and ethical judgment?"

Mukasey, Schumer said, replied: "Absolutely. That is what I am there for."