The three-part drama, which is full of warmth and humour, tells the story of an ordinary family faced with an extraordinary situation.

Eleven-year-old Max identifies as a girl, and as the ticking clock of puberty begins and Max’s belief that he’s in the wrong body intensifies, the fractured family – mum, played by Anna Friel and dad, Emmett J Scanlan – must unite to help Max find a way forward.

During the Q&A which followed the screening, BBC Radio 5 Live’s Nihal Arthanayake asked the key creatives about Butterfly’s topicality and the responsibility of creating a drama around a sensitive issue that has never before been fully explored in a UK television drama.

“There is so much misinformation around, and so many families who have never seen their stories on screen,” said executive producer Nicola Shindler.

Having established it was the right time to tell the story, Shindler took the project to ITV, since it was the broadcaster’s flagship soap, Coronation Street, which introduced TV’s first ever trans character, Hayley Cropper, more than 20 years ago.

Marchant said everyone involved was “really assiduous about the research”, working closely with the charity, Mermaids, and meeting trans people and families “to do justice to the experience of the kids and their families”.

For its part, Mermaids was keen to be involved. Chief executive Susie Green argued that, unlike documentaries, “this was a way of getting the story told without putting any of the young people in a position of having to out themselves or put themselves at risk”.

Marchant hopes that locating the drama in the heart of a family gives it an all-important universality and relatability, so that the audience will invest in the story on three levels: “in Max’s gender dysphoria, in how the family copes, and in the love story between the mum and dad”.

At the heart of the story, are the two young actors playing Max (Callum Booth-Ford) and sister Lily (Millie Gibson). Director Anthony Byrne praised their performances, highlighting how he worked with them, Friel, Scanlan, and Alison Steadman as outspoken grandma Barbara, helping them to gel as a family so they’d “feel like a real family, which is so important in terms of accessibility”.