25/03/2016 2:21 PM AEDT | Updated 15/07/2016 12:51 PM AEST

Ted Cruz Labels Donald Trump "Snivelling Coward" After Attack On His Wife

Scott Olson via Getty Images
DANE, WI - MARCH 24: With his wife Heidi by his side, Republican presidential candidate Sen. Ted Cruz (R-TX) tours the Dane Manufacturing facility before speaking to workers on March 24, 2016 in Dane, Wisconsin. Wisconsin voters go to the polls for the state's primary on April 5. (Photo by Scott Olson/Getty Images)

Ted Cruz has launched one of the angriest and most stinging attacks of the 2016 presidential campaign, labelling opponent Donald Trump "a snivelling coward" after attacks on Cruz's wife.

The Republican presidential campaign has taken an especially nasty turn in recent days, after Trump claimed he would "spill the beans on [Cruz's] wife," Heidi. Trump was responding to an ad produced by an anti-Trump group called Make America Awesome, which shows Trump's wife Melania posing for a GQ Magazine photoshoot in 2000. The images of Melania Trump have since been used in pro-Cruz, anti-Trump online memes, but CNN reports the Make America Awesome group "has no known connection to the Cruz campaign."

Cruz also publicly distanced himself from the photo.

Trump later retweeted a picture comparing an image of Heidi Cruz to a glamour shot of Melania Trump, paving the way for Cruz to launch his extraordinary attack.

Speaking in Wisconsin, Cruz angrily addressed Trump through the media pack assembled to cover his event.

"It's not easy to tick me off. I don't get angry often. But you mess with my wife, you mess with my kids, that'll do it every time," Cruz said.

"Donald, you're a snivelling coward. Leave Heidi the hell alone."