Brash is also a member of the Free Speech Coalition which was formed after a decision was made by Auckland Council to ban the speakers from its venues.
But, the speech notes provided by Brash make no mention of Hobson's Pledge or the controversial Canadian duo.
Instead it details his political career through to his decision to step down as National leader in late 2006.
Massey University vice chancellor Jan Thomas today said the decision to cancel the speech came after the Politics Society raised concerns about their ability to meet the conditions agreed to as a result of a surge in interest on social media.
READ THE SPEECH NOTES HERE:
Brash told Larry Williams on Newstalk ZB he was defending the right to freedom of speech, not the opinions that Southern and Molyneux share.
"The irony is, I to speak about my time as National party leader between 2003 and 2006, I wasn't talking about current events at all.
"In my speech notes, I make no reference to the Canadians or to the Hobson speech or anything else," he said.
Prime Minister Jacinda Arden weighed in on the Brash and Massey University conflict, stating that it was an "overreaction on the part of the university".
"There'll be a number of examples over the years where politicians and ex-politicians have gone on to campuses and there has been a bit of a stir around their views and people using their voice to either protest or support," she said.
Brash is no stranger to controversy with his infamous Orewa speech making headlines in 2004 when he was leader of the National Party.
In it he criticised "separatist" policies such as the allocation of Māori electorate seats in Parliament and the use of Māori spiritual traditions in official events.
Brash will speak at an event on Thursday night held by the University of Auckland Debate Society, focusing on the issue of freedom of speech.
President of the society Chris Ryan told the Herald the event will be going forward as planned despite recent freedom of speech cancellations.
"It's just kind of happened that the timing of the event has coincided with Stefan Molyneux and Lauren Southern and Massey University.
"Freedom of speech was always going to be an interesting thing to talk about. It's kind of gained extra relevance," Ryan said.
The event is being supported by the university and has generated a lot of discussion but no threats had been made Ryan added.