• ‘Taking a leaf out of Trumpism’: Yumi Stynes on the ‘misguided’ backlash to sex book

The book has been criticised by campaigners including Rachael Wong, the chief executive of Women’s Forum Australia, an organisation critical of pro-trans activism. Speaking to 2GB’s Ben Fordham on Tuesday, Wong called it a “graphic sex guide for children”, adding that she felt “physically ill at the thought of children reading it”. Other conservative media figures have amplified the criticism.

“This book was a response to genuine questions asked by adolescents to [magazine column] ‘Dolly Doctor’ for more than 20 years. [Dr Melissa Kang, one of the co-writers], was exposed to what kids were too ashamed to ask anyone else.”

• Big W has withdrawn Welcome to Sex from its stores to protect staff – but teen sex education can keep young people safe

Critics have taken particular issue with small sections of the book that address inclusive sexual practices beyond penetrative sex, including “fingering”, “oral sex”, “scissoring”, and “anal sex”.

They are also critical of the inclusion of what they term “gender ideology”. Others are accusing the authors of “grooming” children – a term that is increasingly misused.

• 'I make no apologies': Yumi Stynes responds to Welcome to Sex critics

The backlash has been so intense Big W stopped selling the book in-store after staff members were abused, although the retailer has defended it and it remains available online.

"I've seen people saying to me 'I want to kill you' or 'You should die'," Stynes told SBS News.