An Oxford college has been accused of closing down free speech over its plans to host a discussion about transgender issues which bans “language which denies the validity of trans identity”.

Merton College has advertised its upcoming “Equality Conversation” event which it says will explore “perspectives on trans intersectionality”.

Yet in order to reserve a place at the event, attendees must sign up to a code of conduct which states they must “refrain from using language or putting forward views intended to undermine the validity of trans and gender diverse identities”.

This is likely to include the view that there is a difference between sex and gender identity, as well as the view that those who are biologically women are not exactly the same as transgender women who are biologically male but identify as female.

Academics have accused Merton College of adopting a “draconian” stance towards free speech by “suppressing gender-critical thought”.

Prof Selina Todd, a historian at Oxford University, said she was “stunned” by the event’s rules, adding that it sets a “dangerous precedent”.

“My understanding is that universities and colleges are supposed to be upholding free speech,” she said.

“Merton College seemed to me a place where you could debate calmly and an informed matter, and the way this has now been couched as 'you're not allowed to debate' has left me staggered.”

She said it is “very worrying” that a reputable university college such as Merton has made such an “overt statement that debate is not welcomed”.