The Catholic church has banned a visit to a London school by a gay author and removed a number of governors who supported the event, in a move that has drawn comparisons to the notorious 1980s section 28 ban on “promoting homosexuality”. The church said a visit by Simon James Green, an acclaimed author of books for children and young adults, fell “outside the scope of what is permissible in a Catholic school”. Green had been due to speak and sign books on Monday at John Fisher boys’ school in Purley, south London, a voluntary-aided faith school overseen by the Catholic archdiocese of Southwark. A second event at another school, St John’s primary in Gravesend, scheduled for Wednesday, was also cancelled. Green told the Guardian that he “didn’t think this sort of thing could happen in the UK today. I was at school when section 28 was in force. So I know full well the horror of living under that legislation. But it was repealed in 2003. So I didn’t think a school today would go down that route.” Section 28, which prohibited local authorities from “promoting homosexuality”, was introduced by Margaret Thatcher’s government in response to a children’s book, Jenny Lives With Eric and Martin, depicting different kinds of families. In a statement issued a few days before the John Fisher event, the archdiocese said its schools were required to “deliver a programme of relationships and sex education that is compliant with the Equalities Act 2010 and Magisterium [teaching] of the Catholic church”. It added: “From time to time, materials or events emerge for consideration that fall outside the scope of what is permissible in a Catholic school … In such circumstances, we have no alternative but to affirm our unequivocal and well-known theological and moral precepts and to act in accordance with them.” However, the school’s leadership team, backed by its governors, voted to go ahead with Green’s visit. The archdiocese then cancelled the event and removed a number of governors. The school’s chaplain, Father James Clark, emailed parents to say the proposed event had “caused scandal in the local area and has brought our international reputation into doubt”. The email, seen by the Guardian, added: “The headteacher and some governors have decided to disobey the clear instruction from the diocese and this will have serious consequences in the weeks ahead,” and saying that the school “had no choice but to make a stand against tyranny and to defend truth”. Catholic Truth, a Catholic website, also campaigned against the event, saying: “Catholic schools cannot, under any circumstance, endanger the faith of pupils in their charge by presenting as a good, something which is condemned by the divinely bequeathed teaching authority of Christ’s church.” One parent told the Guardian: “A lot of us are shocked at the intolerant language being used. It sends a terrible message to the children. Who would want to come and teach here or send their children here after this?” The NEU and NASUWT teaching unions at the school passed a motion saying they believed the archdiocese’s decision violated the UN convention on the rights of the child. Members were “concerned about the mental and emotional impact these events have had on our LGBTQ+ community and wider inclusive John Fisher school family, including staff, students and parents”. A spokesperson for the NEU said the cancellation of the event and the decision to remove some school governors was “a matter of grave concern”. The union would be writing to the archdiocese “calling for the reinstatement of both the governing body members and for the visit by Simon James Green to be allowed to go ahead”. Green said his response to the church’s actions was disbelief. “There was initial shock and dismay and hurt, but after that it was the students I felt most worried for. I know what it’s like to be a teenager at school, questioning yourself, and how vulnerable that can make you.” His books for young adults were novels featuring LGBT characters, with some “soft romance” but nothing explicit, he said. His books for younger readers celebrated underdogs but contained nothing about LGBT issues. Green said he hoped the school events could be rescheduled. He decided to speak out “because if you don’t, there can be creeping sense of people feeling emboldened in the future, and things getting worse”. Stephen Evans of the National Secular Society said: “The disturbing behaviour of this diocese highlights a broader problem of faith schools stigmatising same-sex relationships and therefore contributing to a climate where many young LGBT people are growing up feeling ashamed or frightened about who they are. “Our own research has shown that a significant number of faith schools promote the idea that same-sex attraction is ‘morally wrong’, ‘disordered’ or a ‘lifestyle choice’. This isn’t acceptable in a publicly funded school.” Robert Cann of Humanists UK said the archdiocese was “discriminating against a well-regarded children’s author, whose work has been celebrated far and wide, simply because his work promotes LGBT acceptance. The result is that children, including LGBT children, are missing out on learning that LGBT people should be celebrated, and their relationships should be respected just like those of straight people. “Dioceses should not have the power to block lessons that promote inclusion under the Equality Act, and they should not be able to sack governors who support such lessons.” A spokesperson for the Department for Education said: “We are looking into the circumstances surrounding the diocese’s role in this incident … Schools should teach students that everybody has the right to be treated with dignity and respect, with particular regard to their duties under the Equality Act.” The archdiocese of Southwark and John Fisher school have been contacted for comment.