National supporter's sign ripped off him at Jacinda Ardern walkabout at Canterbury Uni

Labour leader Jacinda Ardern's visit to the University of Canterbury has led to an angry confrontation after a student turned up with a "Vote National" sign.

Ardern was mobbed by hundreds of students in the recreation room of the university, with more students crowding balconies to get a look at the Labour leader.

While that was happening, a few metres away things turned ugly when National supporter Jacob Putson turned up with his homemade blue sign.

After booing, another student took particular offence to Putson and confronted him - pointing his finger in his chest and asking him who else in the room supported National.

He then ripped Putson's sign off him, throwing it on the ground and coming close to shoulder bumping him.

Jacob Putson turned up with his homemade blue sign. Photo / Nick Jones

Jacob Putson was a lone Nats supporter among a sea of red. Photo / Nick Jones

Afterwards, Putson said it showed the left didn't respect the right to free speech.

"I'm not ripping the signs off the Labour Party. The left try to monopolise free speech and morality.

"I think it is an attack of free speech and free expression. The right are much more tolerant of the left's views and we don't go ripping signs down. That man there was absolutely in the wrong right now."

It all made for more of a distraction for the lines of students who were playing chess on a rainy day when Ardern arrived.