The Open University was forced to cancel a conference on prison reform following threats from the transgender lobby, it has emerged.

Over a hundred delegates had already bought tickets for the two-day event in May, which was co-organised by the Centre for Crime and Justice Studies (CCJS). But earlier this month, attendees and speakers were notified that the conference had been called off.

The CCJS, an educational charity, has been accused of “transphobia” for its stance that transgender female prisoners should be incarcerated separately from female prisoners.

“The Open University faced quite significant pressure from transgender activists. They received a number of emails where some of the language was extraordinarily overheated,” a source told The Telegraph.

“They were effectively being threatened with demonstrations and disruptive activity, possibly in the conference hall itself, and some kind of picket line or protest outside the conference.”

Last month, the CCJS released a statement on transgender prisoners which said that prison service has “a duty to provide fair, decent and respectful provision for trans prisoners”.

It went on: “Given the current state of the prison system, in the case of trans women prisoners, we consider that this can best be achieved through the provision of accommodation that is separate from female prisoners.”