Camilla Bray may have come across a new genre with her first feature film as lead producer: she describes Kenny Glenaan's Summer as "an adult coming-of-age story".

She explains: "It's about two best friends who live together as adults and have been partners in crime since they were young. Daz (Steve Evets) gets ill so Shaun (Robert Carlyle) has to look over his life and reflect on his relationships." The film also revisits the pair as teenagers during one pivotal summer, where they find themselves bored in an economically depressed English town.

Summer has its world premiere at the Edinburgh International Film Festival on June 22 and Vertigo is planning a UK release later this year (the film had its market premiere in Cannes; The Works International is handling sales).

Bray, who works out of Ken Loach and Rebecca O'Brien's London-based production company Sixteen Films, saw the script because frequent Loach collaborator Paul Laverty knew Glenaan and first-time feature writer Hugh Ellis.

While Loach is famed for his political and social film-making, Bray notes Summer's social issues are in the background to its story of friendships. "There's an economic and social context," she says. "But it's ultimately about relationships."

Summer's $2.7m (£1.4m) budget was backed by EM Media, Scottish Screen, UK Film Council's New Cinema Fund, and equity investment from Cinema Two. The German co-producer was Mediopolis, and the project shot in Derbyshire and Yorkshire.

Having Loach and O'Brien first as her mentors, starting in 2003, and now as colleagues has been invaluable. "Ken gave me great advice when I was a rabbit in the headlights," she says of Loach's help on Summer. O'Brien, who became Bray's mentor when she was still in the producing MA programme at National Film and Television School, executive produced the film along with Matador's Nigel Thomas. "I've seen the confidence and trust Rebecca has in her creative team," Bray says of her former mentor.

Bray has no plans to strike out on her own yet, if ever. "I don't need my own banner, I like to benefit from that community," she says of her colleagues at Sixteen.

She is talking to Ellis and Glenaan about future projects together, and she is also readying her second production: Empty Cradles, to be directed by Ken's son Jim Loach, a TV veteran. Rona Munro, who also wrote Ken Loach's Ladybird Ladybird has finished the script, and an Australian co-producer is being brought on board.

The story is based on social worker Margaret Humphrey, who championed the cause of poverty-striken UK children who were misleadingly told they were orphans and shipped from the UK to Australia in the 1940s and 1950s. The $5m project is likely to shoot mostly in Australia in 2009. "It's an Erin Brockovich-type story," Bray says. "It's about a real miscarriage of justice."