WASHINGTON — Michael Mukasey, President Bush's nominee for attorney general, told senators Thursday he's resistant to passing a law shielding reporters from being forced to reveal their sources, saying it would be much easier to fix internal Justice Department practice if need be.

"The system worked passably well up until now," Mukasey told the Senate Judiciary Committee, which approved legislation that would establish such a shield. The House overwhelmingly passed a similar bill last week, but President Bush said he would veto it.

Mukasey, a former federal judge who also has represented reporters as a defense lawyer, indicated he would side with Bush against any federal legislation.

"One thing about internal procedures is that if you need to change them they're relatively easy to change," he said at his confirmation hearing. "You can adjust the regulation, you can adjust the procedure, you can put more levels in. You can change standards. It becomes much harder when it's etched in stone in the form of legislation. And that is part of the reason for my unease."

His comments on the second day of confirmation hearings that have veered over myriad topics and Justice Department controversies under Alberto Gonzales, the last attorney general, who resigned in August.

Majority Democrats, aided by some Republicans, have urged passage of a media shield because they say it would protect reporters and government whistleblowers who reveal improper or illegal official activity. Fifty news outlets, including The Associated Press, support the legislation.

The Bush administration has issued a veto threat, saying that subpoenas for reporters are relatively rare and that a shield would make it harder to track down leakers of classified information.

Mukasey said that he has reservations about the legislation because it sets too high a legal threshold for prosecutors to meet to overcome the shield. Proving that the disclosure is needed to prevent an attack is difficult in advance, the nominee said Wednesday.

The measure also pending defines a journalist too broadly and might inadvertently protect, for example, bloggers who are also spies or terrorists, Mukasey said.

Sen. Arlen Specter, R-Pa., who supports the shield, asked Mukasey to submit his specific objections to the committee in writing. Mukasey agreed.

The exchange opened what was expected to the the final round of questioning of Mukasey. Later in the day, the panel was set to hear from witnesses that included former Attorney General Dick Thornburgh.

So far, Mukasey has told senators he will reject any White House meddling in Justice Department matters and resign if his legal or ethical concerns about administration policy are ignored.

Senators of both parties liked most of what they have heard. Republicans even grinned at his answer when Sen. Jeff Sessions, R-Ala., asked him whether he also would challenge the Democratic-led Congress if need be.

"I'm not a bashful person," Mukasey replied during the proceedings Wednesday in his second day of confirmation hearings. "I'm not going to become a bashful person if confirmed."

Right from the start of his confirmation hearings, Mukasey made clear that he would keep partisan politics out of federal law enforcement, a stark contrast with how the 110,000-employee agency operated under Gonzales.

Appointed to the federal bench by President Reagan, Mukasey, 66, said he would review opinions issued by the department's Office of Legal Counsel to make sure they are legally sound. He described as "defective" a 2002 memo that defended the Bush administration's use of torture techniques against terrorism suspects.

"It purported to justify measures based on broad grants of authority that were unnecessary," he told the panel Wednesday

Likewise, on politics, Mukasey said he would discourage his prosecutors from bringing charges against political candidates shortly before elections and would not let party loyalty be a consideration for people applying for Justice Department jobs.

"That's the standard I'm going to make very clear, very precise, and I'm going to enforce," Mukasey said.

It was a far cry from the policies Gonzales allowed before he resigned in September after months of criticism and questions about his honesty.

An internal Justice Department investigation is looking into whether Gonzales lied to lawmakers about the administration's terror programs and illegally let politics influence hiring and firing of Justice Department employees. Gonzales, a close friend of President Bush and a former Texas Supreme Court justice, has denied any wrongdoing.