Outgoing Arizona GOP Sen. Jeff Flake joined with Democrats on Wednesday in a failed bid to force a vote on legislation to protect Special Counsel Robert Mueller -- and locked arms again with the other side of the aisle to oppose a judicial nominee, resulting in an airtight vote requiring Vice President Pence to serve as tie-breaker.

Flake, along with Delaware Democratic Sen. Chris Coons and New Jersey Democratic Sen. Cory Booker, tried to use a parliamentary maneuver to pave the way for a vote on the Special Counsel Independence and Integrity Act, which would shield Mueller from inappropriate removal or political pressure.

Flake asked for unanimous consent to vote on the bill, but Utah Sen. Mike Lee objected, blocking the effort.

The three lawmakers expressed concern over comments made by President Trump, who has called the Mueller probe a “phony witch hunt,” as well as Trump’s ousting of Attorney General Jeff Sessions.

“It’s clear, therefore, something has to be done to protect Mr. Mueller’s investigation,” Flake said on the Senate floor.

The Special Counsel Independence and Integrity Act mandates that a special counsel can only be fired for good cause by a senior Justice Department official.

Some Republicans counter that the bill is unnecessary. During Tuesday’s briefing, White House Press Secretary Sarah Sanders denied that the president is considering firing Mueller.

“Look, I think that the president has had Robert Mueller doing his job for the last two years, and he could’ve taken action at any point, and he hasn’t. So we’ll let that speak for itself,” she said.

Sanders added, “He has no intent to do anything.”

The blocking of the bill, though, is complicating GOP efforts to confirm Trump’s judicial nominees. Flake, who is retiring from the Senate, has said he won’t support any of Trump’s judicial nominees until he gets a vote on his Mueller bill.

Flake followed through on Wednesday afternoon and joined Democrats opposing a bid to advance Thomas Farr’s nomination to serve on the federal bench for the Eastern District of North Carolina.

Pence was then forced to break a tie, in a rare Senate intervention by the vice president.

A final confirmation vote is expected later this week.

The Farr nomination has been controversial, with all 49 Democrats opposing Farr, arguing that Farr discriminated against African Americans through his rulings on voting laws.

“Mr. Farr defended North Carolina’s absurdly restrictive voter ID law, also passed by the conservative Republican state legislature, and they tailored their election laws to disadvantage African-American voters after requesting race-specific data on voting practices,” Senate Democratic leader Chuck Schumer of New York said.

Republicans, meanwhile, are standing behind Farr.

“The American Bar Association’s Standing Committee on the Federal Judiciary -- a body that's frequently been held up by my Democratic colleagues as the ‘gold standard’ -- has awarded Mr. Farr its highest possible rating: unanimously well qualified,” Senate Majority Leader Mitch McConnell said.

Fox News’ Chad Pergram contributed to this report.