A writer-director from Stanmore in Middlesex whose short film has been nominated for an Oscar has said he feels “utterly overwhelmed” by the accolade.

Lee Knight’s film A Friend of Dorothy, starring Miriam Margolyes and Stephen Fry, is in the running for best live action short.

“This is a tough business where rejection is constant and it can be hard to stay afloat. But as storytellers we must never give up,” Knight, 42, told the Guardian. “We have a duty to put our stories out into the world for all to see. I hope this sends a message to any artist who feels their voice isn’t worthy.”

The 22-minute film is a heartfelt intergenerational story of loneliness and unexpected friendships. Margolyes plays Dorothy, an elderly widow whose lonely life is transformed after a teenager accidentally kicks his football into her garden.

Through their shared love of reading and reciting plays, they strike up an unexpected friendship. Alistair Nwachukwu plays the young neighbour JJ, and Oscar Lloyd plays Dorothy’s grandson.

The film is inspired by Knight’s own friendship with a lonely widow, Shirley Woodham, who lived next door to him and his husband in a former council house until her death in 2022 aged 89.

Its title is taken from the code used by gay people during times of persecution, Knight said, noting that it conveyed his early feelings of being an “outsider” as a gay man.

He said: “I wanted the film to be an ode to a sanctuary place for someone that’s in the closet. ‘Friends of Dorothy’ was a coded way of describing gay men because Dorothy in The Wizard of Oz and her friends like the Tin Man were all a bit different. They were all misunderstood.

“For me, being a gay man and being bullied when I was younger and finding sanctuary with older women, I always felt safe with women. This story is an ode to the Dorothys in our lives and safe spaces to ‘be ourselves’. I’d always found that with Shirley.”

He added: “Her husband had passed away, her son and daughter lived abroad and she was very lonely. She’d supported theatres her entire life, as a ‘friend’. So we had this wonderful friendship. We took her to the theatre. We also looked after her. We became very close. I wrote this film inspired by that relationship.”

Knight spoke of the “power of human connection, regardless of the differences we may perceive between one another”.

Stephen Daldry, previously nominated for best director Oscars for Billy Elliot, The Hours and The Reader, is the film’s executive producer. He said: “Lee’s an old friend. This is a big career-defining moment for him – his first short film nominated for an Academy Award [is], I think, astonishing.”

In a world where there was such a divide between the generations, he said, he found the film “incredibly moving”. He described Margolyes’ performance as “wonderful” and predicted Nwachukwu would be “one of the major actors of his generation”.

Daldry said: “I’ve seen him [Nwachukwu] quite a few times, both on stage and on screen. I think he’s phenomenal and a real talent.”

Knight has had acting roles as Rosencrantz to Ian McKellen’s Hamlet and in one of the Harry Potter films. But he did not know Margolyes, another Potter cast member, when he wrote the script. He said he was astonished when she agreed to do it.

Asked how his neighbour Woodham reacted when he told her she had inspired a film script, he said: “She thought it was hilarious. She just laughed her head off. I gave her the script. I don’t know if she ever read it.”

After her death, her son found the script among her belongings and encouraged Knight to make the film.

The production is supported by the charity Age UK, whose chief executive, Paul Farmer, said: “While Dorothy might be a fictional character in this instance, there are so many real older people out there for whom this extremely lonely existence is their stark reality – and many will not be lucky enough to meet a friend like JJ.”

The film-makers intend to extend the film’s reach to schools and care homes across the country.