A three-day women's festival to be held in March next year at Mount Martha, south-east of Melbourne, has been criticised for not allowing transgender women to attend unless they have undergone gender re-assignment surgery.

Seven Sisters Festival is described by organisers as "the only one of it's [sic] kind on the planet that provides you and a select few women with an extravagant wonderland to EXPLORE, GROW AND EVOLVE".

Kylee, who did not want her to use her full name as her partner Belle is in the early stages of transitioning, wrote to festival organisers last month to ask whether Belle would be welcome.

"We've been trying to become more involved in women's circles so that she can feel more comfortable, but at the moment she's retreated a bit from life, so I thought a really beautiful camping festival with all women would be a really safe place for her to feel accepted," she said.

She said after messaging and emailing the organisers a number of times, she was told that her partner would not be welcome at the event.

"Their basic response was 'we only welcome trans women who are post-op, who have undergone all the procedures to become a woman, because having people onsite who are physically male, would break the trust of the attendees'," she said.

"I got quite ragey over it, and I read it out to my partner and she just kind of sighed and went 'yep, that sounds about right'."

Kylee's partner Belle said while she was not surprised by the festival's response, it was disappointing.

"The [email] was talking about surgery - so only rich, well to do trans women who can afford the full gender re-assignment surgery which is upwards of $20,000 by the time you do everything are considered female?" she said.

"Having spent a lifetime feeling like a woman to finally be brave enough to start to make the changes to do something about that, to then have the very people who you are aspiring to be part of their community lock you out, it's not a very nice feeling."

Seven Sisters Facebook backlash

Kylee said she did not respond to the email, but she posted it to the event's Facebook page weeks later, after another woman asked whether transitioning women could attend.

Since posting the email, the event organisers have been criticised and labelled transphobic by a number of people on the page.

The post and Kylee's response have since been deleted.

Belle said she hoped that next year, the festival's policy would change after the backlash to their policy.

"And it makes me really happy to see people that are cisgender, or in a different position of privilege, speaking out for that recognition," she said.

The ABC has contacted the organisers of Seven Sisters festival for comment.

In a post on the event's Facebook page organisers said they would respond to concerns about their transgender policy via email "within working hours".

"We appreciate everyone has an opinion and freedom of speech, however we don't condone any abusive and violent language, therefore we have deleted and will delete any post that are inflammatory and abusive," the post read.

"This is an issue we are taking very seriously and will be addressing with consideration."