Speaking at the Pink News Awards in London, the Prime Minister told a star-studded audience that changes will be made to the Gender Recognition Act in order to reflect updated attitudes towards being transgender.
She said: “We are pressing ahead with inclusive relationships and sex education in English schools, making sure that LGBT issues are taught well.
“We're determined to eradicate homophobic and transphobic bullying.
“We have set out plans to reform the Gender Recognition Act and streamline and de-medicalise the process for changing gender, because being trans is not an illness and it shouldn't be treated as such.”
The Conservative leader drew rounds of applause for her announcement, and for the mention of Justine Greening's role as Education Secretary.
Ms Greening, who was also present for the ceremony, was the first openly gay woman to serve in a UK Cabinet.
Mrs May said there is “still a long way to go” in defeating prejudice against LGBT communities, but pledged to push for greater understanding to avoid the “terrible suffering” found in other parts of the world.
She said: “Trans people still face indignities and prejudice - when they deserve understanding and respect.
“And when we look around the world, we see countries where the human rights of LGBT people are denied and terrible suffering is the result.”
Collecting her award for Politician Of The Year alongside co-winner and Scottish National Party MP Hannah Bardell, Ms Greening thanked attendees and recalled how she had announced her sexuality on Twitter in the wake of the Brexit vote last June.
She said: “When I sent that tweet last year I did it because I realised that I needed to be part of the solution and part of helping things move on.
“But I got a huge amount of support from so many people in this room and outside and it really inspired me and encouraged me to do what I can in my own powers, not only as a minister for equalities but as Secretary for Education - which is the best job in Government.”
She added: “The best thing is, there are now so many politicians in our Parliament which are part of this cause and part of changing things for the better.
“And that, in the end, is what is going to move things on.”
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