They exist in many countries and are often affiliated with either the International Fellowship of Evangelical Students (through a national body) or the Campus Crusade for Christ.
Some UK Christian Unions have had difficult relationships with the students' union due to their policy of allowing leaders to choose their successors in order, they argue, to ensure a Christian leadership (students' unions often require democratic processes be followed), opinions on issues such as homosexuality[1] and the role of women,[2] and the requirement that leaders affirm a fixed conservative evangelical[3][4][5] Doctrinal Basis.
The latter includes doctrinal statements that go beyond the historic ecumenical creeds, e.g. recognising the Bible as the sole authority, and belief in penal substitution.
As well as hosting traditional talks and debates, they may hold unconventional events such as "Text a Toastie".
[8] These particular events involve providing a number to students, to which they text a question about God, the bible, or Christianity more generally, and in response two members of the Christian Union deliver a toastie to them and answer their question.