Joe Biden told a member of the public they were “full of s**t” during a confrontation over gun control in Michigan on Tuesday.
The Democratic frontrunner made the comments during a tour of a car manufacturing plant in Detroit, as primary voting in the swing state was already underway.
A video of the incident shows what appears to be a worker in the factory approach Mr Biden and accused him of “actively trying to diminish our Second Amendment right and take away our guns.”
Mr Biden responds: “You’re full of s**t. I support the Second Amendment.”
He then tells an aide to "shush" while he argues with the man.
“I’m not taking your gun away, at all,” he continued, before adding that he was in favour of restricting the sale of assault rifles.
Mr Biden then referenced the “AR-14” rifle as an example, apparently confusing it was the notorious AR-15 assault weapon, which has been used in a number of high profile mass shootings.
The incident came on the same day that Mr Biden received his third endorsement from a major national gun control group in as many days.
The Newtown Action Alliance, which was founded after the Sandy Hook Elementary School shooting in Newtown, Connecticut, said the former vice president’s "support for gun violence prevention has never wavered."
Mr Biden is favourite to beat rival Bernie Sanders in Michigan’s primary.
