"It seems to me the Democrats have locked down in their determination to keep him from getting confirmed," Bennett said in an interview.

"I don't think we'll take another vote unless senators come up to [Senate Majority Leader] Bill Frist and say we're ready to change."

Democrats have twice blocked a vote on Bolton's nomination, refusing to budge unless the White House agrees to release intelligence memos and information from Bolton's tenure as the top arms control official at the State Department.

Critics allege Bolton tried to manipulate intelligence reports and intimidate analysts. He probably would have the backing of a majority of the senators, but Republicans have been unable to win the 60 votes needed to break the Democratic filibuster.

Both Bennett and Sen. Orrin Hatch were among a group of senators who met with Bush on Tuesday, when the president pressed Frist not to abandon the Bolton vote.

"The president said he wants an up or down vote and I certainly support that," Hatch said, adding that it was "obscene" the way Democrats were using the system to block Bolton.

"It looks to me like the Democrats will continue their obstructionist tactic of filibustering," Hatch said. "They are undermining the U.N. by not getting a tough guy there. . . . The U.N. is out of control and Bolton would be able to do some things about it."

Senate Minority Leader Harry Reid said Wednesday that Democrats are willing to cooperate.

"If the president turns over the information - not part of it or a summary of it - but turns over all the information requested, the White House will get their up or down vote on Mr. Bolton," Reid said Tuesday.

White House spokesman Scott McCellan said the administration has tried to cooperate with the Democratic senators by making available portions of the classified information Democrats are seeking.

"What happens is they continue to change their request and change their demands for information," McClellan said.

"So I think it's clear the Democratic leadership is not interested in working in good faith and finding the middle ground. They're only interested in moving the goal post and in blocking John Bolton's nomination from proceeding forward."

Bush could still make a recess appointment of Bolton, which would allow Bolton to serve as ambassador through the end of the current Congress without Senate approval.

"The decision whether to send him to the U.N. on a recess appointment is entirely up to the president, and he did not discuss that with us,'' Bennett said. ''He is going to keep his own council on that."