Mike Lee makes urgent plea for Mitt Romney's endorsement in Utah Senate race

• "Please get on board. Help me win re-election. Help us do that," said Lee, who is seeking his third term in the U.S. Senate.

Yes, but: Romney has maintained he would stay neutral in the race.

• "I've worked with Mike a lot and appreciate the work we do together. But both are good friends, and I'm going to stay out," he previously told Politico.

What they're saying: "I don't think Mitt Romney wants [Democrat] Chuck Schumer to continue to be the Senate Majority Leader," Lee told Carlson, adding that Romney's support would help Republicans seize control of the U.S. Senate.

• Lee added he feared voters would be "duped" into voting for McMullin, who is being backed by the Utah Democratic Party.
• "Does anybody else think @MikeLeeforUtah is starting to sound *really* nervous?" McMullin responded via Twitter.

Details: During the segment, Carlson repeatedly slammed Romney, accusing the senator of "working against" Lee in the competitive race.

Between the lines: Romney's neutrality in the race was magnified last month after Lee announced a list of 48 other GOP Senators supporting his campaign.

• "Sen. Lee sees it as important for all members of the party to stand together and he welcomes the public endorsement of all of his Senate GOP colleagues, including Sen. Romney," Lee's campaign advisor Matt Lusty said in a statement.

State of play: A day after the segment aired, former President Donald Trump sent out a campaign email reiterating his "complete and total endorsement" of Lee, while condemning Romney and McMullin.

What we're watching: Lee and McMullin are set to debate Monday, Oct. 17 at Utah Valley University at 6pm.