Republican frontrunner Donald Trump threatened on Tuesday to go after the wife of rival Ted Cruz after a conservative anti-Trump super PAC used the real estate mogul's wife in a negative ad, prompting Cruz to call Trump a "coward."
"Lyin' Ted Cruz just used a picture of Melania from a G.Q. shoot in his ad," Trump posted on Twitter on Tuesday night. "Be careful, Lyin' Ted, or I will spill the beans on your wife!"
Cruz, whose campaign was not responsible for the ad, fired back at the threat.
"Pic of your wife not from us. Donald, if you try to attack Heidi, you're more of a coward than I thought. #classless," Cruz wrote back on Twitter, before doubling down on that criticism Wednesday.
"If Donald wants to get in a character fight, he's better off sticking with me because Heidi is way out of his league," Cruz said in an interview with CNN on Wednesday morning. "It reveals a lot about character, reveals a lot about class that Donald's instinct is to try to attack my wife and sully her."
The ad, paid for by Make America Awesome super PAC, ran on Facebook and was aimed at Mormon voters ahead of Utah's caucuses on Tuesday, BuzzFeed reported.
"Meet Melania Trump. Your next first lady," the ad says atop a photo of the former supermodel. "Or, you could support Ted Cruz on Tuesday."
Cruz clinched a strong victory in Utah on Tuesday.