Banning Christian societies from campuses is an illegal act, Anglican and Roman Catholic Bishops have warned student unions last night.
The warning followed decisions by student guilds and associations at three universities, Exeter, Birmingham and Edinburgh, to suspend Christian groups from membership or use of premises on the grounds that their constitutions or meetings are exclusionary and discriminate against non-Christians and particularly gay people.
Other university unions, including Heriot-Watt University and some London medical schools, are said to have taken similar action.
The director of Share Jesus International, the Rev Dr Rob Frost, criticised the bans which he called "a great tragedy".
He told Christian Today: "The loving, serving and gracious ways in which the Christian Unions have carried out their ministry over the last 80 or more years is to be applauded.
"The fact that they are now being pushed off of university campus property, and out of the mainstream of student life is a great tragedy."
Dr Frost upheld the right of the Christian Unions to freedom of speech but warned that they have been facing increasing oppression over the last five years.
Edinburgh University banned an event run by the Christian Union called PURE which promotes a traditional biblical view of personal and sexual relationships.
The university defended the ban, saying that PURE was in breach of its equality and diversity policy because PURE claims that any sexual activity outside heterosexual marriage is not God-ordained.
The pressure came principally from the Gay and Lesbian Society at Edinburgh University and follows the university's decision last year to ban copies of the Bible in its halls of residence after protests from the students' union.
The Lawyers' Christian Fellowship criticised the decision to ban PURE, saying, "This incident is an attack on freedom of speech in an institution where an open exchange of views and a search after truth should be strongly upheld.
Calls for the groups to be reinstated were made in a letter signed mainly by evangelical Church of England bishops and organisations including the Evangelical Alliance, and the Roman Catholic church's lead bishop on higher education.
The Christian unions at two universities have threatened legal action.
The 1986 Education Act imposes obligations on universities to safeguard the lawful exercise of freedom of speech and a universities' working party's guidelines for student unions, published in 1998, state that unions shall not harass, intimidate or threaten any member or group.
The Universities and Colleges' Christian Fellowship, umbrella body for 350 university Christian unions representing up to 20,000 students, said the organisations were under "unprecedented" attack.
