More than 100,000 people had by Thursday signed an online petition demanding the UK prison authorities move a transgender woman out of an all-male prison on grounds of safety.
According to the petition on change.org, 26-year-old Tara Hudson, who is serving a 12-week sentence for assault in a bar fight, has lived her entire adult life as a woman.
The petition says the Bristol prison where Hudson is being held is a particularly violent one and that she faced "extreme danger of abuse, sexual violence, and even death".
"People like Tara Hudson are still paying a high price at the hands of an outdated and outmoded judicial system, simply for being who they are," it said, asking that she be moved to a women's prison.
Hudson has undergone six years of reconstructive surgery and is considered a woman by her doctor but is still awaiting final reassignment surgery and does not have formal recognition of the change.
A prison service spokesman said offenders were placed "according to their legally-recognised gender".
"However, our guidelines allow room for discretion and in such cases, medical experts will review the circumstances in order to protect the emotional wellbeing of the person concerned," he said.
"Additionally, there are strict rules in place to ensure transgender prisoners are managed safely and in accordance with the law," he added.
Campaigners estimate there are between 20 and 30 transgender people in British prisons at any one time and say they face a higher risk of abuse.
"It's totally outrageous. I don't think she will cope well at all," her mother, 48-year-old Jackie Brooklyn, told the Bristol Post.
"I just feel the men are going to go after her. It's going to be humiliating," she said.