By Jennifer Newton for MailOnline

Students who were campaigning for free speech on campus had their protest shut down after a police officer threatened to ‘lock them up.’

The two students along with an adviser from organisation Turning Point USA were handing out copies of the U.S. constitution at the College of Du Page in Illinois.

They had also been asking fellow students to sign a petition urging the college to adopt a less restrictive policy on free speech.

It came after one of the students Joseph Enders, had been trying to set up a Turning Point USA club at the school, but to no avail.

But despite one of the students proudly holding up an American flag, a campus police officer appears telling them to immediately stop their protest saying they need a permit to hand out leaflets.

In footage of the exchange, one of the students challenges the officer saying, ‘it’s not free speech?’

But the officer replies: ‘Nobody’s stopping you from free speech, but you can’t solicit out here, and basically you are — you’re soliciting your opinions. Okay? And you need to go get a permit.’