Green Party nominee Jill Stein was escorted off the Hofstra University campus Monday night, after protesting that she wasn't invited to the debate between Hillary Clinton and Donald Trump.

"We were on our way to an interview with @MSNBC when we were stopped by Hofstra security and Nassau County police just now," Stein tweeted Monday afternoon. "We were immediately escorted off of the Hofstra campus after the press conference just now and told not to do any more press."

A spokesperson for the Nassau Police Department later told CNN that Stein was removed from the campus because the candidate lacked the proper credentials to be there.

We were immediately escorted off of the Hofstra campus after the press conference just now and told not to do any more press. #debatenight pic.twitter.com/ZFr49NPMuH — Dr. Jill Stein🌻 (@DrJillStein) September 26, 2016



Stein had planned a series of demonstrations at Hofstra University in Hempstead, N.Y., several days in advance. She and her supporters pushed for Stein's entry into the debate.

Stein later retweeted video of demonstrators being arrested at one of her rallies.

We were on our way to an interview with @MSNBC when we were stopped by Hofstra security and Nassau County police just now. #debatenight pic.twitter.com/Y0fQjih47Y — Dr. Jill Stein🌻 (@DrJillStein) September 26, 2016



"This is not what democracy looks like," Stein wrote.

Stein, like Libertarian nominee Gary Johnson, failed to reach the 15 percent polling threshold to qualify to appear on the debate stage with Clinton and Trump.

But not being able to have a physical presence on the stage isn't stopping Stein from being able to "participate" in the event.

Stein's campaign said she will "participate" in the debate, which begins at 9 p.m. EST, via social media in a partnership with Twitter on Periscope, and livestreaming on her Facebook homepage.