The Senate Judiciary Committee approved legislation on Thursday to expand the authority of the Justice Department inspector general over opposition from Sen. Lindsey Graham (R-S.C.) and the Department of Justice (DOJ).

The committee voted 21-1 on the legislation, which would give the DOJ watchdog the authority to investigate attorneys within the department. Graham was the only senator to vote against the measure.

The vote sends it to the full Senate, where supporters acknowledge they don't know if it will get taken up for a vote in the face of opposition from Graham, who chairs the Judiciary Committee, and Attorney General William Barr.

Graham tried to change the legislation to require the attorney general to sign off on investigations into potential DOJ attorney misconduct.

"I'm not going to support legislation that allows an IG to investigate discretionary decisions at the Department of Justice. If there's a dispute about misconduct between the IG and the attorney general, the last word will be the attorney general who is politically accountable," Graham said of his proposed change.

Graham noted that he had spoken with Barr about the legislation three times. He said the attorney general did not support his proposal either but DOJ Inspector General Michael Horowitz did.

"I don't think he's ever going to get to yes on any process that allows the IG to look at DOJ lawyers and people under their charge,” Graham said of Barr.

But the committee voted down his amendment, instead passing the bill as originally written by Sens. Mike Lee (R-Utah) and Dick Durbin (D-Ill.).

Sen. Dianne Feinstein (Calif.), the top Democrat on the committee, argued that Graham’s amendment would give the attorney general “veto power” over an inspector general's work.

The vote comes after the bill was held up in committee for weeks as supporters of the legislation tried to negotiate a compromise with the DOJ, which did not immediately respond to a request for comment.

Lee said that they tried to negotiate in “good faith,” but didn’t want to agree to water down their bill if the DOJ wasn’t going to support it anyway.

"The Department of Justice has not agreed to this compromise. It's time to take an up or down vote as written,” he said. "We shouldn't be asked to compromise without any compromise on the other end.”

Durbin added that DOJ “hates this ... like the devil hates holy water.”

"It makes no sense to weaken this bill without the attorney general's support,” he said.