A motion to stop the four-day Wilberforce Academy being held on campus received overwhelming support from members of the Junior Common Room (JCR) at Lady Margaret Hall.
The organiser, Christian Concern has publicly spoken out in favour of traditional marriage and Biblical-centred education, while publicly opposing abortion.
Its legal arm - the Christian Legal Centre - has been involved in several high-profile court battles including the case of Sarah Kuteh - a Christian nurse who offered to pray for patients and was dismissed by the NHS.
Eighty-one JCR members voted in favour of the ban, with eight voting against it and two abstaining.
Christian Concern was accused during a debate of posing a "real threat to the physical and mental safety of students" and proclaiming a message at odds with the university's values.
Open to students and young professionals from various backgrounds - including politics, law and media - the Academy aims to "equip the next generation of Christian leaders in public life".
Organisers say on the Wilberforce Academy's website: "Our aim is that delegates will be prepared for servant-hearted, Christ-centred leadership in public life, having been equipped with a robust biblical framework that guides their thinking, prayers and activity in addressing the issues facing our society."
A final decision will be made by Lady Margaret Hall's governing body next week.
Premier has contacted Christian Concern for a comment.
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