A controversial University of East Anglia union event where UK Independence Party members were due to speak has been postponed because it had not been approved.

The union, which was due to hold a political society event where UKIP's Norwich South candidate Steve Emmens was due to speak, has said it is in discussions to reschedule the debate.

It comes after an online petition was launched to try and stop the debate being held on the Norwich campus.

Timea Suli, an international public policy and public management student, has gathered more than 1,150 signatures on an online petition calling for an event with UK Independence Party members to be barred from the Norfolk university's campus.

The event had not been organised by the university, but by its political debating society, and was set to be held in a lecture theatre tonight.

This afternoon, the union posted a statement on its Facebook page saying a procedure governing the approval and handling of events with external speakers was approved by the Trustee Board last year, but was not followed.

A spokesman said an 'internal investigation' had been held.

Adding: 'The review will consider the potential for any decision to limit freedom of speech as per the university's code of practice in pursuance of the 1986 Education Act; the potential for the event going ahead to cause the union to be in breach of its equal opportunities policy; the potential for the event going ahead to cause the union to fail in its wider legal duties; the potential for the event going ahead to cause reputational risk to the Union; the potential for the speaker's presence on campus to cause fear or alarm to members of the student body; and the potential for the speakers presence on campus to give rise to breach of peace. Consultation with interested parties will be carried out.'

Following this consultation the union will then decide whether the event can go ahead, and if so in what form, in accordance with procedures.

Former UEA student Douglas Carswell, who was the first elected UKIP MP following a by-election in Clacton, said: 'It is sad that in 2014 there should still be people who want to ban ideas and prevent free speech. It is patronising to suggest students need protecting from UKIP, a genuinely reformist party offering us real political reform.

'As a former UEA student, I am looking forward to speaking at an event at the university in the New Year. I hope anyone fed up with our failed political system might come along and discuss how we can change things.'

UKIP's Norwich South Branch chairman, Eric Masters, commenting on the cancellation said: 'We were delighted to have been asked to by the Political Society to go along and explain who we are and what we stand for. The invitation was given and accepted in good faith. The abrupt cancellation, almost at the eleventh hour on 'procedural grounds,' suggests that it is a reaction to lobbying from some members of the Students Union, including the publication of a potentially libellous petition. If true, it amounts to the worst kind of political censorship.

'It was an event organised by the Political Society. If the Society cannot invite a mainstream political party that came first in a national election in May, with nearly 4.5 million votes, to speak at one of its events, then something has gone badly wrong at UEA. The University is an educational establishment and, as such, it should be committed to a balanced approach to political studies.

'Our door remains open. If the Political Society can sort out the internal issues at UEA, we are still willing to go along and speak to the students, so they can make up their own minds about us. However, if that doesn't happen, it is pretty clear that censorship is alive and well at UEA and that its students are being prevented from obtaining a balanced understanding of mainstream British politics.'