The National Union of Students has pulled out of a seminar tomorrow at the London School of Economics because it refuses to share a platform with one of the speakers.
The seminar will examine new religious movements and the growth of "cults" on campuses. When the NUS learnt this week that a presentation would be given by the Islamic movement Al-Muhajiroun, its speaker was withdrawn.
Verity Coyle of the NUS executive, who was scheduled to give a presentation, said: "It is NUS policy not to give a platform to Al-Muhajiroun because of their incitement to violence on campuses."
She added: "Students feel strongly enough about this organisation to have singled it out because of the threat of racial tension and hatred. Student safety has to be our paramount concern."
The only other group subjected to a "no platform" policy by the NUS is the British National Party.
The conference organisers are Inform, a charity based at LSE to research new religious and spiritual movements.
Eileen Barker, professor of sociology at LSE, said it was not Inform's mission to make judgements about religious movements but to inform people openly. Speakers have been invited from other controversial groups such as the International Churches of Christ and the School of Economic Science.
"There are questions that can be raised about new religious movements that are on campus with the intent of attracting new members to their groups," Professor Barker said. "What kinds of methods do they use? How honest are they about who they are and what they believe and practise?"
Marion Bowman of the Open University's religious studies department said she was concerned about "accreditation" of new spiritual practitioners.
"There are a large number of lectures and workshops offering training and qualifications in various types of healing... This is a new growth industry of qualifications and there are more and more people with letters after their name who are members of academies and institutes that look legitimate," Dr Bowman said.
One new course Dr Bowman spotted led to a qualification in tasseography - tea leaf reading.