- There has been a row over whether Prof Kathleen Stock should be allowed to attend the debate. Some say her views on gender identity are transphobic.
- And Oxford University's LGBTQ+ Society called for a protest at the venue ahead of the event.
A gender-critical academic says she is "determined" to speak at the Oxford Union after some students responded angrily to her invitation to a talk.
There has been a row over whether Prof Kathleen Stock should be allowed to attend the debate. Some say her views on gender identity are transphobic.
And Oxford University's LGBTQ+ Society called for a protest at the venue ahead of the event.
Prime Minister Rishi Sunak said Prof Stock's invitation should stand.
He added: "Agree or disagree with her, Professor Stock is an important figure in this argument. Students should be allowed to hear and debate her views.
"University should be an environment where debate is supported, not stifled.
"We mustn't allow a small but vocal few to shut down discussion."
Prof Stock said she was "very determined to go ahead" with the debate.
She said it was "important that people can hear what I have to say", adding that she is "standing up to authoritarians who want to silence debate".
The LGBTQ+ Society has asked for Prof Stock's invitation to be rescinded, calling the event part of a campaign of hate against transgender people.
Prof Stock rejects the claim her views could be classed as hate speech.
She said: "It's not hate speech to say that males cannot be women.
"You can believe what you like, and I'm not stopping anybody believing any different, but it's certainly not hate speech to say that and that's basically the most controversial thing, I think."
Prof Stock believes controversial views should be tested in public.
"It's important younger generations are exposed to ideas they haven't come across before. Sometimes that will be very challenging to them," she said.
"Controversial and difficult ideas need to be tested in the public square, we need to think about them properly and we also need to enable discussion of ideas that seem attractive to people because if you try and shut it down there will be massive public resentment."
Prof Stock left her job with the University of Sussex in 2021 after protests against her from students following the publication of a book where she questioned the idea that gender identity is more socially significant than biological sex.
Some students have criticised her views as being transphobic.
Dr Michael Biggs, associate professor of sociology, says censorship on campus threatens the very core of what universities are about, adding it is "absolutely crucial you understand views you disagree with".
"I tried in the past to host meetings around the Gender Recognition Bill [in Scotland], and it was shut down."
Dr Biggs says many academics have told him they have avoided teaching about sex and gender because they are worried about the student response.
"The problems really come from the fact that academics had been too cowardly in the past.
"I think more academics are realising this is a problem and are standing up."
Amiad Haran Diman, president of the university's LGBTQ+ Society, said they had received death threats in the post after speaking out against Prof Stock's invitation to the event.
"We have received thousands of comments online. Some of them very homophobic, very transphobic, hateful, threatening," they said.
"We have seen activists coming here with cameras just to harass students. We have seen unprecedented abuse to our small community, just because Kathleen Stock is coming here and she decided to tweet about it."
Zoë-Rose Guy, the society's vice-president, said it had been "the most crazy few weeks of my life" and that she had endured "sleepless nights".
Ms Guy said she supported Prof Stock's right to free speech, but said speaking at the Oxford Union was a "privilege not a right".
Oxford Union president Matthew Dick backed the decision to host Prof Stock and said people who "just want to incite hate" would not be invited to speak while he was in post.
"We look to not just hear from people who are just famous or well known but people who do shape the conversation in certain ways - and that goes to certain academics," he added.
Oxford Union has said attendees at the event will have an "opportunity to respectfully engage and challenge" Prof Stock's views, as well as being able to ask questions anonymously.
But Ms Guy said it was "exhausting" as a trans person to be "constantly expected to justify your existence".
The LGBTQ+ Society said the planned protest outside the Oxford Union would not be a "hate campaign" against Prof Stock, but a "festival celebrating trans joy and kindness".
The Oxford Union is a private members club that University of Oxford students and others pay to join. It is independent of the university and the student union.
There had been speculation that a recent decision by the student union to split with the Oxford Union debating society was due to Prof Stock's invitation.
But the Oxford University Student Union said the decision was unrelated.