In 1986 somebody came across a children’s book in a library in Haringey, North London. It was called Jenny Lives with Eric and Martin and it showed a child living with her father and his male partner. This book would become a firing shot for a culture war: a war about what kind of country Britain was becoming.

It would engulf the newly-created Haringey Lesbian and Gay Unit, local parents, the tabloid press, Parliament and Margaret Thatcher herself. She said that: “Children who need to be taught to respect traditional moral values are being taught that they have an inalienable right to be gay.”

Eventually, it would result in a law banning the ‘promotion’ of homosexuality by local authorities and by schools. Section 28 of the Local Government Act – enacted in 1988, at the height of the AIDS epidemic.

The actor Michael Cashman, who campaigned against the law, goes back and tells the story behind it. How and why a local issue turned into a media sensation, created a movement, and sparked a battle over sex education that continues today.