Students at Oxford University are calling for the firing of a law professor after he compared gay sex to bestiality.

More than 400 people have also signed a petition calling for John Finnis to be removed from teaching.

The 78-year-old is emeritus professor of law and legal philosophy at University College.

Finnis has said in 1994 homosexuality is ‘never a valid, humanly acceptable choice and form of life’.

He wrote in his collected essays, published in 2011, that it is ‘destructive of human character and relationships’.

He also added: ‘[Gay sex] treats human sexual capacities in a way which is deeply hostile to the self-understanding of those members who are willing to commit themselves to real marriage.’

Finnis, who converted to Catholicism in 1962, has previously advised the Vatican.

He has also called homosexuality ‘evil’, ‘destructive’ and similar to the abuse of children.

Finnis has also encouraged ‘gay cure’ therapy said approving of LGBTI rights is similar to approving terrorism.

Students signed a petition calling on Finnis to be removed from teaching compulsory lectures.

‘It puts a hugely prejudiced man in a position of responsibility and authority,’ they say.

‘It makes people who are affected by his discrimination question whether they should even attend these seminars…

‘University is a place to focus on education, not to be forced to campaign against or to be taught by professors who have promoted hatred towards students that they teach.’

Finnis told the Oxford Student: ‘I stand by all these writings. There is not a ‘phobic’ sentence in them.

‘The 1994 essay promotes a classical and strictly philosophical moral critique of all non-marital sex acts and has been republished many times.’

Alex Benn, one of the authors of the petition, said Finnis had ‘built a career on demonisation’.

Benn also told the Oxford Student: ‘Campaigns like this one often receive simplistic responses calling for tolerance or academic freedom. But law, employment and education already draw boundaries about what won’t be tolerated.

‘The humanity of disadvantaged people, including LGBTQ+ people, isn’t a debate …

‘I started this campaign not only to address the specific issue of Finnis’ role at Oxford, but to get Oxford to make up its mind – either it’s in support of equality or it’s not.”

A university spokesperson said: ‘Oxford University and the faculty of law promote an inclusive culture, which respects the rights and dignity of all staff and students.

‘We are clear we do not tolerate any form of harassment of individuals on any grounds, including sexual orientation.

‘Equally, the university’s harassment policy also protects academic freedom of speech and is clear that vigorous academic debate does not amount to harassment when conducted respectfully and without violating the dignity of others.

‘All of the university’s teaching activity, including that in the faculty of law, is conducted according to these principles.’