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A Democratic Alaska senator facing a tough reelection is doing all he can to hold onto his seat, but his latest attempt to buddy up to his GOP counterpart has backfired spectacularly.

Sen. Mark Begich, D-Alaska, recently received a cease-and-desist letter from an attorney for Republican Alaska Sen. Lisa Murkowski after the Democrat’s re-election campaign created a television ad touting them as a dynamic duo.

“Senator Begich should run on his own record and not attempt to deceive the public into believing he has support that does not exist,” the letter said.

The letter marks an unusual rebuke for Begich from the other half of the Alaska Senate delegation, as he prepares to face a tough Republican challenge following next week's GOP primary.

The offending Begich ad, titled, “Great Team,” features Republican Navy pilot Skip Nelson, who claims his support of Murkowski is leading him to vote for Begich, despite the fact that Begich is a Democrat.

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“Lisa Murkowski and Mark Begich vote as much as 80 percent of the time together,” Nelson said. “I don’t think we ought to break up that team.”

However, Murkowski has a message for Begich: I don't even want you to win.

Last week, Scott Kendall, the attorney for Murkowski's campaign committee, demanded in a letter that Begich immediately stop using Murkowski in his ad.

“You attempt to use this image to somehow imply Senator Murkowski’s support," the letter reads. “This is far from true. Senator Murkowski has repeatedly made clear she wants a Republican elected to Alaska’s other Senate seat.”

However, Begich defended the ad to NBC News, saying it is a fact that he and Murkowski have voted together 80 percent of the time. A representative for Begich did not respond to requests for comment from FoxNews.com.

“And that is laying out what we've been saying and what Alaskans have been telling me they love, and that's a delegation working together,” he said.

According to PolitFact, Begich’s campaign calculated the 80 percent figure with data from Begich and Murkowski's voting records from 2014. Out of those 183 votes, the Alaskans agreed 148 times and disagreed 35 times.

Begich’s Senate seat is listed by Real Clear Politics as one of nine “toss-ups” in the November general election.

On the Republican side, the latest polling shows former Alaska Attorney General Dan Sullivan leading against Alaska Lt. Gov. Mead Treadwell, Joe Miller and John Jaramillo in the Republican primary on Aug. 19.

A recent PPP poll, though, showed Begich with a narrow lead over his potential GOP challengers.

FoxNews.com's Stephanie McNeal contributed to this report.