A cage fighting event at Wembley Arena is facing calls to be banned because of its "ultraviolent" nature.
Mr Blackman said cage fighting has no place in modern Britain
Bob Blackman, London Assembly member for Wembley, north London, said the "medieval human blood sport has no place in modern Britain".
Mixed martial arts combat is big business in the US and has grown in popularity in the UK in recent years.
Wembley Arena said the event will go ahead and measures were in place to ensure the safety of participants.
The tournament, called Cage Rage, combines elements from Thai Kickboxing, Brazilian Jiu Jitsu and freestyle Wrestling.
Each fight consists of three five-minute rounds taking place inside a cage ostensibly to stop the fighters falling out of the ring.
There is a full set of rules, and each bout is refereed.
Mr Blackman called on Wembley Arena to cancel the event as a gesture to local residents.
"The 'sport' of cage fighting offers no protection to its participants and it excites the worst sides of human emotion in those who watch it," he said.
A statement from Wembley Arena said it took the "utmost care to ensure the heath and safety of all participants, visitors and staff at any event staged at the arena".