‘Did you notice when you said the word feminist an alarm went off?’

When Deborah Levy arrives in the foyer of a London hotel, it’s hard to miss her. Wild blonde hair, red-lipped and wearing layers against the snow that threatens, she asks the receptionist in a very low voice where I might be found. Her voice, it transpires, is one of the reasons she became a writer. “I was very soft-spoken at school,” says Levy sipping an espresso, “the more they shouted, the quieter I became.

“Eventually a teacher suggested to me that I should write down what I was thinking and when I did, they seemed like very loud thoughts. When I started to write, I actually began to speak louder – my own volume literally went up.”

Perhaps because of this, Levy speaks in an almost conspiratorial manner. Her writing is very similar, boasting a directness that’s hard to turn away from, but there’s nothing quiet about her written words.

Last autumn, the Man Booker Prize judges agreed, hoisting her novel Swimming Home on to the shortlist. Hilary Mantel’s fluid, meticulously researched Bring Up the Bodies won the prize, but Levy’s arch, exceptional novel of a family in crisis was the best book on the shortlist.

Levy admits to being surprised at the Booker attention, not least because Swimming Home has, in publishing terms, a great back story. “The book had been declined by a handful of publishers for being ‘too literary’. As soon as I met Stefan [from independent publishers And Other Stories], I knew he was the real deal and that he would take good care of my book.”

Born in South Africa in 1959, Levy was an ardent reader before gravitating toward a writer’s life. Her father was a historian, but the family’s life was later overshadowed by political unrest. Her mother – “the serious reader in the house” – had a huge influence on the books her daughter consumed. “In my teens I used to comb the bookshelves at home looking for ones that might have some sex in them. I took down Edna O’Brien’s Country Girls books and devoured them.”

Sex surfaces in an oblique way in Swimming Home , when a poet and his war-correspondent wife decamp to France with their daughter. Their brittle marriage is complicated by the arrival of an attractive young stranger who has an incendiary effect on their lives.

“When I finished writing it, I was shaken to the core. I was a different writer to the one who started it, and that surprised me. I knew I was going to have to create a very definite sense of place because strange things were going to happen in that place. Kitty was going to hallucinate that someone could actually walk through walls.”