I have stolen this from twitter and tweaked it.
I am an atheist: my belief is that no deity exists.
Despite it being offensive to them,
I am not forced by religious people to believe in any gods
I am an atransgenderist : my belief is that no-one can ever change their sex.
Despite it being it being offensive to some, I cannot be forced to believe anyone can change their sex.
I cannot see a difference between these two statements - a religious person may define themself entirely in terms of their religion as a trans person identifies themselves wholly in terms of their gender id yet the first will be permitted and the second not.
#mumsnettransphobia is an attack on free speech.