WASHINGTON – Prospects for Michael Mukasey’s confirmation as the nation’s 81st attorney general dimmed yesterday after he again refused to equate waterboarding with torture and more Democrats on a key committee announced they would vote against him.

Freshman Sen. Sheldon Whitehouse, D-R.I., announced from the Senate floor that he would oppose Mukasey’s confirmation.

The retired federal judge’s refusal to say that the interrogation technique is “unconditionally wrong” would leave open the possibility that U.S. agencies could cross a moral and legal line and use it on detainees, Whitehouse said.

He laid the blame for Mukasey’s answer at President Bush’s feet.

“If we allow the president of the United States to prevent or to forbid a would-be attorney general of the United States … from recognizing that bright line, we will have turned down that dark stairway,” Whitehouse said. “I cannot stand for that. I will oppose this nomination.”

Senate Majority Whip Dick Durbin, D-Ill., also a member of the Senate Judiciary Committee, followed Whitehouse to the floor to add his opposition to the tally.

That brings to three of nine committee Democrats who will vote against Mukasey on Tuesday, when the panel considers whether to advance the nomination to the full Senate for confirmation. Sen. Joe Biden, D-Del., announced he would vote no earlier this week.

Their announcements resolved a frenzy of behind-the-scenes vote-counting on Mukasey, whose nomination seemed assured just two weeks ago. Key Democrats, and the committee’s ranking Republican, were staying mum.

Even his chief Democratic patron, Sen. Chuck Schumer of New York, refused to say whether he would vote for Mukasey next Tuesday during the Judiciary Committee’s consideration of the nomination.

“I’m not going to comment on Judge Mukasey here. I’m reading the letter, I’m going over it,” Schumer told reporters yesterday, hours after the retired federal judge submitted more than 170 pages of elaboration on his positions.