More Daily Mail anti-trans hyperbole. God forbid anyone use more inclusive language around transgender birth parents.
The document isn't telling anyone what language to use it's suggesting that language be inclusive where appropriate.
"In our language we will aim to add and not take away, taking into account the importance of preserving women-centred language as well as including language for those who do not identify as a woman."
Then it points to the diversity policy which does not mention "assigned at birth."
"Assigned at birth" the government's defintion and has a legal meaning.
The UK government defines sex as:
referring to the biological aspects of an individual as determined by their anatomy, which is produced by their chromosomes, hormones and their interactions
generally male or female
something that is assigned at birth