A speech titled 'Honour Killings are Morally Justified' by Sydney-based Muslim speaker Uthman Badar from Islamic group Hizb ut-Tahrir, supposedly to be delivered at the Festival of Dangerous Ideas 2014 ignite social media outrage.

On Tuesday night, festival co-curator Simon Longstaff announced that Sydney Opera had decided to cancel the speech due to the height of people's outrage.

"The justification for removing it was simply the level of public outrage.We took the view that it was so strong and overwhelming that the ability of the speaker to even open up the question for some discussion and reflection would be impossible. It would be unfair for the speaker to put them in a situation where they wouldn't get a word out without finding all of condemnation," Longstaff said.

Posting in his Facebook account, Badar described the outrage as mere hysteria and as reflection of Australia's Islamophobia.

"I anticipated that secular liberal Islamophobes would come out of every dark corner, foaming at the mouth, furious at why a Muslim 'extremist', from Hizb ut-Tahrir no less, was being allowed a platform at the Sydney Opera House to speak. What's interesting is that I'm being attacked left, right and centre without having opened my mouth yet. " Badar posted.

Sydney Opera House also released its official statement through Facebook.

The institution explained that the Festival of Dangerous Ideas is intended to provoke thought and start a sound discussion. The festival, according to the post, is not intended to just provoke as in the case of the cancelled 'Honour Killings are Morally Justified' speech.

"It is always a matter of balance and judgement, and in this case a line has been crossed. Accordingly, we have decided not to proceed with the scheduled session with Uthman Badar. It is clear from the public reaction that the title has given the wrong impression of what Mr Badar intended to discuss. Neither Mr Badar, the St James Ethics Centre, nor Sydney Opera House in any way advocates honour killings or condones any form of violence against women," the statement reads.

During the announcement of the festival, Sydney Opera House described the session with Badar as an examination of the condemnation of honour killings and the cultural view of honour itself.

The Festival of Dangerous Ideas 2014 will be held from August 30-31.