"This advertisement is factually incorrect," Murkowski's lawyers wrote in the letter. "It also misuses Senator Murkowski's image, and implies her support, without her permission -- and, in fact, over her known objections."
According to Hunt, Begich said that the image is an Associated Press photograph and the ad doesn't violate Senate ethics rules or federal law.
Murkowski also complained to reporters last month that Begich had been talking up their alleged alliance.
“I just think he needs to run on his record -- and not mine,” she told Politico. Begich disagreed at the time.
“The record speaks for itself,” he told Politico. “The votes that we have been taking are showing clearly that we’re one of the few delegations in this whole chaotic dysfunctional Washington, D.C., that actually vote together more often than anyone. That’s a fact.”