Massey University has cancelled a Don Brash speaking event over safety and security concerns.

The former politician and Hobson's Pledge founder was booked to speak with members of the politics club at Massey's Manawatu campus tomorrow.

The university decided to scrap the event after becoming aware of social media posts suggesting the event could turn violent.

Don Brash has been vocal in supporting free speech, including the rights of controversial Canadians Lauren Southern and Stefan Molyneux to speak in the country.

Free Speech Coalition spokesman Dr David Cumin joins Leighton Smith to discuss the universities decision.

LISTEN ABOVE AS DR DAVID CUMIN SPEAKS TO LEIGHTON SMITH