Senate Democrats back from a weeklong recess said on Tuesday they were holding firm against allowing a vote to confirm John Bolton as U.S. ambassador to the United Nations until the Bush administration turns over more information on him.

“I think the support is just as strong as it was,” Richard Durbin of Illinois, the Senate minority whip, said after a meeting of Democratic senators.

In the Senate’s last act before leaving for its Memorial Day break, Democrats mustered enough support to block a final vote on Bolton, who they said tried to misuse U.S. intelligence and intimidated or tried to remove intelligence analysts who did not conform to his hard-line views.

Democrats demand the administration turn over more classified material on Bolton, but the White House has refused and accused Democrats of using partisan delaying tactics.

Senate Majority Leader Bill Frist, a Tennessee Republican, said he expected to proceed with Bolton’s nomination “very soon,” but could not say “with certainty” when that would be. He has accused Democrats of using a procedural hurdle called a filibuster to block the confirmation vote.

“I would hope that the Bolton situation is not a standoff,” said Senate Minority leader Harry Reid, a Nevada Democrat. “I hope the president recognizes that he has an obligation” to provide the material, he said.

Republicans who hold a 55-45 majority in the Senate, need to pick up two more Democrats to vote to end the debate on Bolton and go to the confirmation vote. A simple majority was needed to confirm him, which Republicans expected to get.

One of the Democrats the White House is trying to enlist, Joseph Lieberman of Connecticut, said he was sticking with his colleagues’ demands for the information.

“I remain undecided on how I would vote on the Bolton nomination itself but I do think this is a point of principle for the Senate and the public’s right to know,” he said.

Lieberman and Ben Nelson of Nebraska were the only Democrats considering supporting Bolton for confirmation. George Voinovich of Ohio and John Thune of South Dakota were the only Republicans who said they intended to vote against him.

Democrats insist the administration turn over e-mails and other internal communications leading up to testimony Bolton gave Congress on Syria’s weapons. They also want some access to classified National Security Agency intercepts sought by Bolton that contain the names of Americans.

“This is now beyond Mr. Bolton. It’s about whether the Senate should have a right to certain information pertaining to a nominee,” said Sen. Christopher Dodd, a Connecticut Democrat.

Dodd offered a compromise in which the administration would confirm whether certain names were on the NSA intercepts Bolton asked to see. Democrats said they were trying to determine whether Bolton requested the classified intercepts to exact retribution on his opponents.

Dodd said the administration rejected the offer.