One Nation MP Cory Bernardi condemned over anti-trans slur and 'incel' comments at SA protest

A social media video from One Nation MP Cory Bernardi in which he uses an anti-trans slur and describes protesters as a "bunch of incels" has been condemned by organisers of yesterday's SA rally against his party.

WARNING: This story contains language that some readers could find offensive.

Hundreds of people, many of them school students, attended Thursday's event outside SA parliament, which was part of nationwide protests against One Nation and its leader Pauline Hanson.

Mr Bernardi, who was elected to the Legislative Council at the March state election, appeared on the steps of parliament, where he began filming the event before roaming through the protest.

In a video from the event which he later posted on social media, he repeatedly shouted "it's a tranny", and at one point referred to the protesters as "a bunch of incels".

One of the organisers of the SA event, Year 11 student Sam Ats, described Mr Bernardi's comments towards the protesters as "appalling".

"Cory Bernardi is a 56-year-old man who is bullying teenagers and high-schoolers, calling them slurs, recording them without their consent to bully and intimidate people who are trying to make their voice heard," the 17-year-old said.

Another organiser, university student Jordan Armstrong, who identifies as a transgender man, also condemned Mr Bernardi's behaviour towards the protesters.

"Calling them slurs and harassing them, it's actually quite embarrassing for him," he said.

"It was pretty pathetic."

The rally on the steps of South Australia's parliament on North Terrace was one of several protests across the country against One Nation's national leader Pauline Hanson.

Protesters repeatedly chanted "f*** Pauline Hanson".

Asked whether that was inflammatory, Sam Ats responded: "I'd say that saying, 'There's no such thing as a good Muslim' is inflammatory."

Mr Bernardi posted two videos from the event on Instagram, including one in which he described the protesters as an "assortment of weirdos", adding that there were "some 'furries' there".

"I saw some weird-looking chick with pointy elf ears on, uh there was plenty of transvestites and things like that, and they're all chanting for a socialist agenda," he said.

"There were oldies there, and I say oldies, people my age, helping these kids."

In a second video, filmed on the steps of parliament, he described the protesters as "total losers" who "don't want to be at school today" and as "a bunch of incels who are now promoting socialism".

"I'm just going to go down there and say g'day," he said to his phone camera, before roaming through the protest and approaching attendees.

"Why aren't you chanting?" he asked one teenager.

That video was accompanied by Taylor Swift's song I Knew It, I Knew You, which was written for the film Toy Story 5.

The use of the music coincides with controversy in the US, where some of the songs of the pop star, who has been outspoken against conservative politics in recent years, have been removed from social media videos posted by Donald Trump's campaign and the White House.

Mr Bernardi was also the subject of chants on Thursday. After he approached young attendees, protesters began chanting "f*** Cory Bernardi".

Mr Bernardi later told media that the protesters "don't know what they're talking about" and described the gathering as "an assortment of incels, unintelligent, unemployable people".

The ABC has contacted Mr Bernardi and One Nation for comment.