WASHINGTON (AP) – Senate Democrats opposed to President Bush’s nomination of John R. Bolton to be U.N. ambassador are trying to delay a Senate vote with a legislative maneuver that ultimately could lead to a filibuster.

As a result, Senate consideration of the nomination is unlikely before the end of the month, Senate Majority Leader Bill Frist’s spokesman said.

The White House, in pushing for confirmation, has taken the position Bolton was needed badly and promptly at the United Nations to work on reform of the institution.

But Sen. Barbara Boxer of California said Democrats were holding up the nomination to compel the State Department to provide more information about the embattled undersecretary.

Frist’s spokesman Bob Stevenson said it was “an ominous signal,” but that talks would be held with the Democrats to try to work out arrangements for bringing the nomination to the floor.

At the State Department, spokesman Richard Boucher indicated the Democrats’ demands for more Bolton documents would not be met.

“We think that we have provided everything that is relevant to this nomination,” he said.

The nomination was voted out of the Foreign Relations Committee 10-8 on Thursday without an endorsement, and Democrats vowed to take their fight to the Senate floor.

Boxer told The Associated Press on Friday she would use procedural delays until Democrats receive the requested information.

“It is not fair to bring this nomination to the floor for debate and a vote until all the information has been delivered,” she said.

Boxer said the Democrats want to know if Bolton sought the names of U.S. officials whose communications were intercepted by U.S. intelligence, details on the private business activities of a Bolton assistant, Matthew Friedman, and the circumstances of a tough Bolton speech on Syria.

Sen. Joseph Biden, D-Del., who is leading the drive to scuttle the nomination, is backing Boxer’s request for a hold, a legislative device to keep the Republican leadership from beginning debate, his spokesman, Norm Kurz, said.

Asked to assess Bolton’s chances of being confirmed, Boxer said, “I think we can definitely beat John Bolton because, I think, the American people are going to weigh in and make their views known.”

She said she would lift the hold when the Democrats received the requested information. But, she said, “all options are on the table, including a filibuster.”

Boucher said the State Department had cooperated “very extensively” with the committee, but that “there are certain kinds of requests that we don’t feel comfortable producing.”

The reason, he said, was that providing internal communications, e-mails and notes to Congress would have a “chilling effect” on exchanges among officials in the department.

And yet, Boucher said, “we don’t want to turn this into a showdown between branches of government.”

There are 55 Republican senators, 44 Democrats and 1 independent. One Republican, George Voinovich of Ohio, said Thursday he intended to vote against confirmation of Bolton.

Voinovich’s reservations about Bolton – he called him “the poster child of what someone in the diplomatic corps should not be” -prompted the committee not to endorse the undersecretary of state while sending the nomination to the Senate.

Still, the White House said it was confident Bolton would be confirmed.

“We believe there is a majority of the Senate that agrees with the president that John Bolton is exactly the person we need at the United Nations during this critical time of reform,” Bush spokesman Scott McClellan said.

The spokesman said Bush telephoned Voinovich on Wednesday. Neither the senator nor the White House would disclose the details of their conversation.