Co-curator Ann Mossop said the presentation will 'obviously' not advocate honour killings. Co-curator Ann Mossop said the presentation will 'obviously' not advocate honour killings. Photo: Steven Siewet

A speaker at the upcoming Festival of Dangerous Ideas will seek to defend so-called honour killings - the murder of women deemed to have brought shame or dishonour on their family.

Uthman Badar, a Sydney-based Muslim speaker, writer and activist, will deliver a presentation titled "Honour killings are morally justified" and argue that such acts are seized on by Westerners as a symbol of everything they dislike about another culture.

The announcement sparked condemnation on social media from those arguing the Opera House stage should not be used as a platform for such radical and confronting propositions.

Uthman Badar will deliver a presentation titled 'Honour killings are morally justified'. Uthman Badar will deliver a presentation titled 'Honour killings are morally justified'. Photo: Festival of Dangerous Ideas

"This man is being given a platform at a reputable event to apologise for the murder of women," wrote consultant Steve Hind on his blog, calling for a boycott. Mr Badar is speaking alone and will not be debated by an opponent.

Mr Hind said that while Mr Badar has every right to make the speech, "as a free society we have every right to boycott organisations and companies - like the Festival of Dangerous Ideas - that seek to make money from or generate publicity by promoting ideas and speech that we find objectionable or hateful".

Eleanor Gordon-Smith, a writer and ethics student, previously organised a series of talks at the University of Sydney designed to challenge orthodox ideas. She said the inclusion of Mr Badar's presentation looks like a marketing stunt to shock people and prove the festival can live up to its ''dangerous'' title.

"I think it's free speech and outrage for its own sake, not for the sake of seeking truth," Ms Gordon-Smith said. "If it's not hate speech, it's seriously ignorant speech."