A controversial Islamic speaker was due to appear before 300 people at York University's Islamic Society on Wednesday evening.
Yusuf Chambers is a founding member of the iERA (Islamic Education and Research Academy), which organises lectures and speaking tours.
Mr Chambers has previously suggested that sharia law should be used in Britain to allow adulterers to be "stoned to death" and has said "may Allah preserve us" from a "gay gene" that he believes leads to homosexuality.
Hasan Afzal, director of anti-extremist group Stand for Peace, said: "Defenders of Yusuf Chambers' views will claim this is a freedom of speech issue. It is not. It is a decency issue. The university has a duty to protect its students from religious extremism."
A university spokesman said: "We will monitor the situation closely and a senior member of staff will attend the event."
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