An Oxford professor has hit back at students who have called for him to be sacked because of links to an immigration think tank.

Oxford Student Action for Refugees has circulated a petition calling for the 'removal' of Prof David Coleman, an expert in demographics, because of his connections with MigrationWatch.

The students are circulating the petition, claiming that as MigrationWatch has warned about the potentially negative effects of immigration, it is racist.

Prof Coleman condemned what he called "a shameful attack on academic independence and freedom of speech". He said he was upset the petition was being circulated and added that it was "insane" to suggest his research was racist. He said: "This is a result of ignorance driven by prejudice."

Kieran Hutchinson Dean, 19, one of the students behind the petition, said: "We are not expecting the professor to be sacked straight away but we are asking that he refrains from using his academic status when promoting his own views."

University spokesman Maria Coyle said: "Freedom of speech is a fundamental right respected by the university."

"Academic staff have freedom within the law to question and test received wisdom, and to put forward new ideas and controversial or unpopular opinions, without placing themselves in jeopardy of losing their jobs or privileges.

David Coleman has been Professor in Demography at Oxford University for five years.

He specialises in immigration trends and has published eight books and more than 90 papers.