The flagship drama in the BBC’s Gay Britannia season, a collection of programmes to mark the 50th anniversary of the Sexual Offences Act. A 2 x 60’ Kudos production for BBC Two.

In his screenwriting debut, bestselling British novelist Patrick Gale tells two love stories, 70 years apart - stories linked by family and a painting, with a secret that echoes down the generations. Featuring a cast including the Oscar-winning actress Vanessa Redgrave, Man in an Orange Shirt charts the challenges and huge changes to gay lives from the Second World War to the present day.

Man in an Orange Shirt is produced by Kudos for BBC Two. Executive Producers are Diederick Santer for Kudos and Lucy Richer for the BBC. It is produced by Lisa Osborne and directed by Michael Samuels.

My commission to write this show couldn’t have been more fortuitous: Commissioning Editor Lucy Richer let it be known she was after a script reflecting gay male experience in the 20th century, which ideally would have the flavour of a Patrick Gale novel.

Happily she said this to Kudos’s Sue Swift, who just happened to be an old friend from my days of bridge addiction. With such a vast subject, I had to find an involving, intimate story within it and, as with so many of my novels, this was a fragment of narrative from my own life.

When my mother was pregnant with me and preparing for us to move - from Camp Hill Prison on the Isle of Wight to Wandsworth, where my father was to become governor - she found a stash of personal letters hidden in his desk. At first she was amused, assuming they were from an old girlfriend he’d never mentioned, then horrified, as she realised they were from an old school and university friend who had been his best man.

In real life she destroyed the letters, terrified he’d be arrested for what was then an imprisonable offence but also disgusted because, in her ignorance, she assumed this meant he was a paedophile. In true buttoned-up English fashion, she never let him know what she had discovered.

What I’ve done in Man In An Orange Shirt is to take that scene of discovery and wind backwards, imagining the two men’s impossible love for each other being shipwrecked on the demands of respectability and the law. And then I’ve wound forwards from it, imagining what would have happened if my mother had instead confronted my father with the discovery. Readers of my novels will know I’m a psychotherapist manqué, fascinated by the effects of secrets and lies within a family.

Man In An Orange Shirt takes those secrets and lies and imagines the long-range damage they might do if the understandably embittered wife of episode one went on, in episode two, to find that her grandson was yearning for the fulfilment her late husband had never known.

Although it’s brilliant that transmission will coincide with the BBC’s celebration of the partial decriminalisation of homosexuality in 1967, I hope this is much more than just a drama about gay men and their difficulties.

I hope that its two love stories will touch people simply as love stories, and that the torments and frustrations in the family I portray will set viewers wondering about their own ancestors, grandparents and parents - and what secrets and lies they might be concealing.