Jason Gardiner and Neil Morrissey clashed on tonight's Mission Survive as things got tense between the remaining celebs.
The pair went head to head after a tired Neil struggled and ultimately gave up trying to erect a series of hammocks in camp.
The Grantchester star complained that they had been designed by a panel of University Challenge winners after spending hours trying to make just one up.
Watching on, Dancing on Ice judge Jason complained: "I don't understand why they're finding it so hard."
"I think what we've done is s**t and it's as simple as that," Neil said of his own handy work. "It took me three hours to put up three hammocks."
"You're a f**king idiot then," snapped Jason. "I built a teepee, I chopped down all that wood with Sam, and now cutting meat, everybody's pulling their weight."
Neil fumed: "Tomorrow I'm going to take a sitting down job, a job where I can sit down and cut up bits of meat. "
He added to the camera sarcastically: "Well done, he's chopped up four sticks and one chunk of meat. Well done."
Later things got VERY awkward as the pair were assigned together to watch the fire overnight.
Meanwhile ex England footballer and coach Stuart Pearce MBE found things especially tough after a challenging ravine crossing on ropes left him dangling high in the air.
He sought comfort in Les Miserables actress Samantha Barks, telling her: "I'm out of my depth but I'm going to try my damnedest."
Others currently in the show include the former Coronation Street actress Michelle Collins and Arsenal and England Ladies footballer Alex Scott.
Mission Survive airs at 9PM on ITV Thursday nights.