An Auckland venue has cancelled tonight's speaking event involving a pair of controversial Canadian alt-right activists.

The Powerstation, in Mt Eden, said this afternoon that Lauren Southern and Stephen Molyneux would not be appearing the venue tonight.

"We're not having the show," said Powerstation owner Gabrielle Mullins.

She said she did not agree with the two speakers' message. The company had been contacted at short notice about hosting Southern and Molyneux and she knew nothing about them.

After receiving complaints, the venue decided to cancel.

"It goes against quite a lot of things that we say," Mullins said. "They can say whatever they want but personally I don't want it in my venue."

Auckland venue just cancelled tonight’s speech. The venue is known for hosting controversial singers including Marilyn mansion. There have been mass brawls and riots at the venue for 3 decades, according to the hardened owner who has ‘seen it all’ & he cancelled Lauren and Stefan

— Caolan Robertson (@CaolanRob) August 3, 2018

Caolan Robertson, an agent for Southern, told Newshub that "powerful forces" were opposed to the event. He said they could not find another venue.

Southern and Molyneux have posted on social media shortly after the decision.

Yesterday, Molyneux and Southern were pictured arriving at Auckland Airport, posing under a Māori carving at the Arrivals hall.

Newshub said the pair had announced they would be using the Powerstation venue as their event in an email then posted to Twitter.

"We want to thank you for the incredible understanding and patience you've shown as we've had to keep the location of the venue secret for as long as possible," the email reads.

"We look forward to the day when venues aren't bullied for daring to be available and ideas right of Stalin are permitted equal rights to peaceful assembly."

One does not simply walk into a venue in New Zealand... https://t.co/o2kUsGutwc

— Lauren Southern (@Lauren_Southern) August 3, 2018

The pair's on-again, off-again visit to this country sparked a debate about free speech after Auckland Mayor Phil Goff blocked them from using council venues, saying he did not want such spaces used to stir up ethnic tensions.

They cancelled the trip after the setback but later reconfirmed plans to speak here after the promoter found a new venue.

Protests were planned by anti-racism groups outside the Auckland venue.

Protesters have threatened to rally outside the Powerstation venue.

Tamaki Anti-Fascist Action spokesperson Sima Brown-Davis told the AM Show today the pair were "not welcome in Aotearoa".

"We have no room for racism and that Auckland is a diverse city that honours the tangata whenua."

It turns out that you cannot give a speech about free speech in New Zealand.

It turns out that you cannot give a speech about free speech in New Zealand. More details to follow.

— Stefan Molyneux (@StefanMolyneux) August 3, 2018

Police have been seen today conducting a security sweep at the Powerstation and but told Newshub police respected the right to protest and the right to freedom of speech.

"Our role is to ensure the safety of any member of the public," Auckland City District commander Superintendent Karyn Malthus said.

"We want everyone to be safe, so we ask that anyone intending to turn up to the event acts in a peaceful manner and with consideration for others."

Immigration Minister Iain Lees-Galloway has said he personally felt their views were repugnant but that there was no grounds to reject their visas.

He dismissed claims that they had been banned from other countries, saying they were prevented from entering for specific purposes.