In a surprise turnaround, Sen. Jeff Flake (R-Ariz.) joined Democrats in calling for a one-week delay in final voting on President Trump’s Supreme Court nominee, Brett Kavanaugh, to allow for an FBI probe into the sexual assault allegations against him.

“I think it would be proper to delay the floor vote for up to but no more than one week,” Flake said at a Senate Judiciary Committee hearing, after huddling with Democrats.

Despite Flake’s new position, the panel proceeded to approve Kavanaugh’s nomination by 11 to 10, with strong objections from Democrats.

A preliminary vote by the full Senate was originally planned for Saturday, and Republicans were optimistic of Kavanaugh’s confirmation.

But Senate Majority Leader Mitch McConnell must now decide whether to hold the floor vote as planned. Flake’s concerns cast new doubt on the prospects of Kavanaugh’s nomination, particularly because Sen. Lisa Murkowski (R-Alaska) had also called for an FBI probe.

Republicans cannot afford to lose more than one of their members, assuming all Democrats vote against Kavanaugh.

The committee vote came a day after powerful testimony from Palo Alto professor Christine Blasey Ford, who said she was “100 percent” certain that Kavanaugh sexually assaulted her when they were both in high school in the early 1980s. Kavanaugh emotionally and strongly denied the allegation.

Earlier in the day, Flake said he would vote to approve Kavanaugh, a key gesture of support that made the nominee’s confirmation more likely.

Flake said he left Thursday’s hearing with “as much doubt as certainty.” But, “I believe that the constitution’s provisions of fairness and due process apply here as well. I will vote to confirm Judge Kavanaugh.”

But after coming under intense criticism from protesters in the Capitol, Flake appeared to have second thoughts about voting this weekend.

During a committee hearing in the morning, Flake abruptly left with Sen. Chris Coons (D-Del.) to huddle outside the room.

Meanwhile, a key Democrat — Sen. Joe Donnelly of Indiana — said he would oppose Kavanaugh’s nomination. The move by Donnelly, who supported Trump’s first Supreme Court nominee Neil M. Gorsuch, further increases the partisan tone of Kavanaugh’s nomination. It also increases the pressure on key Republican holdouts to support the nomination if it is to be successful on the Senate floor.

“I have deep reservations about Judge Kavanaugh’s nomination to this lifetime position,” Donnelly said, echoing calls from other Democrats for an FBI investigation into Ford’s allegation. “Only 113 people have ever served on the Supreme Court, and I believe that we must do our level best to protect its sanctity.”

Flake and Donnelly were two of several undecided senators. Republicans hold a slim 51-seat majority in the Senate and will need nearly every vote to confirm Kavanaugh amid strong Democratic opposition.

Republicans are confident they will have the 50 votes needed to confirm the nomination, but two key senators have not yet said how they will vote: Republican Sens. Susan Collins of Maine and Lisa Murkowski of Alaska.